When planes leave the Airfield, the order the plane take off changes.

So if you have 2 planes on control group 1 and 2 on control group 2 and you make them take off at the same time, you will end up in different planes taking off each time. So instead of the planes of control group 1 leaving first, it might be the planes of control group 2 that take off first, it can also be that 1 plane of group 1 and 1 plane of group 2 takes off, this will result in delayed attacks when you order them to fight.

you either have them send in 1 by 1, with result of them dying, not killing the enemy vehicle or both.
Or you have the planes you want to strike first be delayed so your other planes might die cause of it.