Isn't the other difference that in coop planes that are not occupied by people will still take to the air while in dogfight an unoccupied slot results in that plane not spawning at all?
I would think that would make balancing number of AI in a given mission problematic as a mission designed for 10 on each side would probably be overwhelming to 2 guys flying a mission.
Taking CloD as example (I dont know how is in ROF - but probable similar):
You can set a dogfight server, put 10 AI to do something, and option to players as join, take these AI or create a new plane (that can be restrict).
Or put 10 AI on runway in "Idle", if player join can take one - if not they stay on runway (and can be despawn with script after X time).
The problem is the concept of "COOP" for "1946 players" involve more that COOP mode, is 1946 COOP + 1946 FMB (that is easy to use) + Hyperlobby. This have this drawbacks (that led to UBiZ00 and Sukhoi users beg to OM to change this in SoW BoB) but in essence is
EASY.
Sokol1