Yes. I take damage all the time trying to avoid planes
I did not say "trying"
In the current model, you do not get any collision damage if there is no collision on your screen. If you avoid the enemy, you won't get hurt by a collision (you still can get shot!)
So again, if you clearly avoid the enemy plane, you still want to get collision damage?
Just for illustration, here a typical asymetrical collision again:

This P-47 pilot's view. Message reads "Lusche has collided with you" (P-51 pilot). Jug didn't get any damage, only the pony did.
"Both take damage" would mean the Jug would go down.
Very same moment on the Pony pilot's screen:
