if you do quick combat in dogfight mode and blow up a plane into pieces, it'll just keep spinning around mindlessly in the air, and another wont spawn until it's in the ground, never seen anything like that happen in IL-2
Particularly true in CFS2, when for some reason, some freeware addon aircraft would read as killed, but carry on doing aimless loops. I haven't seen that in CFS3.
What is best with CFS3 is not actually Quick Combat, but to write a quick and dirty mission using random spawns, and play that as quick combat. You haven't got a clue what's going to appear (the aircraft types will be selected at random according to nationality and fighter/bomber), where from, or how they'll react. Not that's something you CAN'T do with IL-2! And, of course, you can write your own spawns files - which I do, although I'm no ace - so as to produce some really unpredictable stuff, using your entire collection of added aircraft! I've had some really hairy moments that way.