The protection of steel armour is a little bit better than wooden armour. However wooden armour is much heavier than steel armour, reducing precious service ceiling.
A few of my ships in the ~$2500 range, while mostly armoured with steel, used to have a few wooden armour sections for appearance reasons. Removing those sections and replacing them with steel gained a solid 37-40 m of service ceiling. The price difference was maybe about $150, inconsequential compared to the benefit of 40m of service ceiling.
I know these things can be hard to balance and the game is in beta, but wooden armour is worse in every respect.
The problem is that if you are armouring a component that costs, for example, $10 per tile, then the difference between reinforced wood armour and steel armour in cost is $18 vs $16 - practically nothing. Meanwhile steel armour is objectively better. For a modest reduction in HP you gain huge blast protection and significantly reduced weight.
Also feedback from other people would be great. Then I would know how much of this is attributable to my play and design style.
And forgot until now that heraldry can affect armour values, didn't factor that in. That only affects the single player campaign though right?
I've done a few calculations with the current armor in game with weight in mind. Seems steel walls are the most efficient when dealing with smaller weapons. It also completely negates the flamethrower weapon.
I only did light armor comparisons up to the steel armor. Steel armor is extremely inefficient for weight vs hp/protection. Caveat, completely negates the rifle weapon and the flamethrower.
The real issue is that most "light" armors are far too underpowered for practical use. Even steel walls are pretty bad at protecting you from anything larger than a rifle. Most weapons do between 30-120 damage. This means that a steel wall would get annihilated in almost all situations. Flak cannon will do enough damage to disintegrate a steel wall in just over 1 shot. Any thing stronger instantly destroys the armor in 1 shot. At that point it's up to the module up to keep the ship from instantly exploding and even then a module only has 75% (or so) of its initial hp before it risks an explosion.
I have been working on a mod to bring more parts to the game so there is a bit of balance. I've mostly worked on the smaller scale since it's lacking the most.
The smallest flying and fighting ship I could make took up 13 module tiles and 3 Airsailors in vanilla. What I'm working on should drop that to 7-8. A little more manageable for fighter craft but still not ideal. I wanted to see 5-6 block ships if possible.
A good idea is to use flak cannons in your larger craft and go ahead and sacrifice some altitude for armor. The only issue you might have is high level bombers. Other than that the flak cannon should rip apart anything above you as those craft will hardly have any protection if any at all.
Vanilla currently only supports the "all or nothing" type armor system that traditional warships of the past century have used. You either fully protect a module to the extreme or armor the least you possibly can. There's a really small line between that right now.
Not sure if heraldry affects MP
The discussion of light armours versus heavier armours seems like an entirely separate issue. TBH I really have not had much issue with light armour since they got the HP boost. Then again I really have very little interest in building 8 or 6 block ships and the fact that you can't make them very effective does not really bother me. The game might inherently have upper and lower limits on ship size for combat effectiveness. That's totally fine, I don't see any issue with that.
Whereas if an entire class of armour type is objectively inferior it is much more of a real problem. Why have wooden armour in the game if it is consistently worse (still waiting to hear people's experience on this topic).
The problem is especially acute with the case of (medium) steel armour versus reinforced wooden armour. I have already described the issue above, but for those who missed it: For 10 additional weight per tile you get... reduced protection? There is literally no upside (other than the fact that it looks cool). $2 less per tile is irrelevant to the point where I question even mentioning it again.
(light) wooden armour vs steel wall is less pronounced but still the same problem. For double the weight you get about the same level of protection. Not to mention differences in flammability.
And yes the reduced weight makes a difference. Being able to pass overtop other ships is a huge gain for mobility. Conversely, even when I am building a huge heavy battleship I don't want to let the service ceiling drop too much. There is a certain threshold below which you disadvantage yourself to the point where no amount of extra armor and firepower will make up the difference - you might as well just ditch all of the lift and accompanying coal storage (which can make up about 30% or more of a large ship!) and make a land ship instead.
This is why I think you are missing the point: there is a trade off between heavier and lighter armours. I use all classes of steel armour in most of my designs, covering everything in heavy steel isn't viable, and using lighter armour on less important modules means I can use more heavy armor elsewhere, or need less suspendium. There are also certain classes of ships that benefit from using entirely light armour save for critical modules. No such tradeoff appears to exist for wood vs steel, wood is objectively worse. For protection that is equivalent at best, or inferior at worst, you pay with a weight increase that is very costly for airships, whether it means allowing a greater percentage of opponents to pass overtop of you or having to add additional suspendium, coal, crew, and fire points in order to maintain that 60m ~ 70m minimum.
I could go deeper into specific points on which I disagree with you (personally I think steel wall is perfect exactly where it is right now) but it's irrelevant to this thread.
Well if we are speaking strictly about the trade off between 'Reinforced Wooden Armour' and 'Steel Armour' then I'm going to have to disagree about having no upside. HP certainly plays a heavy part in combat sustainability of any craft land or air. But reinforced wood certainly starts to shine when used on landships, but then you have to dabble in max carry weight and that's a whole other story.
From using a ship close to the one in your original post, I worked out that armoring the whole thing with reinforced armor would be $252 cheaper while paying $0.28 per armor HP opposed to $0.14 with steel armor. Really the only reason to use steel armor is if you need it to go a little faster/higher or protect against Rockets, Grenades, or Bombs. Other than that reinforced armor is much better at protecting modules from piecing damage.
In harder/larger campaigns, money starts to be a concern. Saving $1000 on 4 of these ships while having 1650 more armor HP against piercing damage on each ship starts to make it sound like a much more enticing solution. If campaign isn't your thing, multiplayer still benefits from the reduced price as long as you can add a few more modules to your ship before hitting the price limit, yet still maintaining a higher total armor HP and equivalent piercing absorbtion to steel armor. But it's only viable if lift permits so that's your trade off.
IMO with this size ship it's almost more important to keep your command cool down low as the lower altitude ship actually had the advantage having more budget for a second bridge allowing it to stay out of harms reach even with its altitude disadvantage, it was able to stay advantageous. Without the extra bridge, the ships pretty much stalemated and ran out of coal before destroying each other fully.
To fully understand which armor works best is dependent on your craft, play style, budget, and a few other minor factors. But as I pointed out in this post, reinforced wood is not "worse" than steel armor, it just doesn't apply well to the situation you are referring too. If you have a very low weight to lift then reinforced armor is obviously going to be a good choice since lift isn't on your mind. Speed is negligible between the two armors until the ship starts to become decently large. After that, steel armor starts to become a better choice due to the fact that each panel of steel has a much smaller chance of being hit and therefore won't need as much total HP.
Again, many factors that can affect the choice of which armor to use and many reasons as to use each armor. For the current meta, it's mostly balanced as they work good together on ships. As you stated about armoring the important parts and leaving the other parts less armored, this is where the combination of the two armors work wonders. You can apply shipwide resist to Gatling and rifle damage to protect crew while using reinforced sporadically or fully on an essential module to increase its total HP. This may add much needed time to a modules life.
I also feel I need to state that armor itself has no flammability, only the modules underneath, which is why fire is so dangerous. [on paper] A fire shouldn't start on a tile that still has armor HP left but it can spread to tile that still has armor and destroy that tile while ignoring any armor left on it. This makes supply modules dangerous since they cannot be armored and risk a flame-up quite often.
I could be wrong about the fire bypassing armor, but if I am, then it seems these two armors dont last long under the heat judging by how fast fires spread in them. Should probably test a bit more with this and find out.
I hope this helps clear things up a little.
That does give me something to think about, yes.
I'm a bit unconvinced that the extra hp really improves the effectiveness of the armour as much as you claim though.
You might be right but I'm starting to think there's way more to the HP "pool" than I first expected. Just experimented with keels and surrounding modules and found ways to make modules exceed 3x it's stated HP pool and still fly. With keels however, I can make all modules have 1,000+ HP. unforuntately it does not apply to armour whatsoever.
On a more related note, I went ahead and made a little tool for finding out how much armor is really doing for protection. Can find it over in the mod section called "Armour Debug Mod"
I think that you are right that reinforced wooden armour has a use, as an option to provide extra cannon protection on key areas at the cost of added weight.