I B&Z the bombers from high, always faster than my target . Unfortunately, the AI gunners (in Il1946) are far more deadly than they really should be and we will have to wait and see if the same applies in COD, even so, I avoid attacking a tightly packed formation unless there are others attacking too.........(such a coward I know) ..
Even if your mission brief is 'attacking bombers' they will have fighter escort and you may well find yourself embroiled with the fighters.
TBH, just engage in the game, enjoy it!