It seems that boarding is very very powerful, it would be nice if airsailors had a chance against them, perhaps airsailors should be capable of fighting back (I'm not sure if they already do, since I have never been unsuccessful in a boarding attempt). Maybe if each marine was worth 2 or 3 airsailors in combat, it would balance out?
the air sailors already do fight back as far as I know. You can usually see it when only 2 or 3 air marines make it onto the ship. Besides, do you think you could fight back against 10 or 15 well armed professional soldiers? :)
Are you using guard barracks on your ships?
Boarding does seem pretty powerful, but I wonder if it's just because many of the AI ships don't have any guards? Some of my bigger, better guarded ships seem to fare much better against assaults.
...And it does make sense to have guarded ships during war.
It's not me who is having the problem with the boarding, it is the AI ships, since they usually do not have any guards. I'm sure it is much different if you're playing PVP though.
I've been working on adding more guard barracks to AI ships, but it's possible I need to do that even more.
Oh and yes, airsailors do fight back, they're just not nearly as good at combat.