Wab you seem to be not seeing the real goal of war. It is to win, not kill the other guy. For any ground mission, the best way to accomplish it is ALWAYS, not fight the other guy if possible.
People almost always would rather attack then defend. So if you make the out come very painful, both sides will just wish to attack more to give pain to the other side,in your thoughts you miss the idea that people will do what they find most fun, not what will stop the other guy from killing their fun. I.E. it's more fun to hurt the other guy, then to try not to be hurt. If the painful goal is accomplished against them they will log out because people will not want to play if the current play is pain full.
but we have now gone off topic and this is best for a different thread.
HiTech
Fair enough, philosophical games design discussion for another time. I’ll bring the scotch.

But in the specific context of the WWI arena, would airfield raids be a good compromise?
You aren't avoiding the fight if you are going directly to where the enemy lives.
No one would risk the ack to raid a field where no one was at.
It prevents the ack huggers from hiding under an impenetrable force field.
It’s temporary.
No base is taken or permanently damaged.
It’s a king of the hill sort of thing. Tear stuff up, make a lot of noise, start some fires. Sirens, gun fire, chaos. Defenders upping manned ack positions. Then fuel, ammo and damage force a retreat. The victims now plan to get even. I’m not suggesting hangars are down. I mean they are burning and stuff but people can still spawn planes and a certain number of ack.
Also, if you have a configuration more like DA furball lake, the cost of pushing all the way to one base will be exposing your flank to the third team, making it even harder to sustain the raid for long.
Anyway, I think having the option to raid an airfield would add to the fun. The WWI is fine the way it is. Its meat and potatoes. I’d just like a little A1 please.

Regards,
Wab