balance it by making field ack more acurate and the bombsights less acurate
drop the ord to kill a hanger down to 1,500 lbs so things like the mossie 6 or P-40N can kill hangers
I think the current system is set up adequately. If I were to use P40's to bust hangars, I would organize a mission. Bearing in mind that P40's would get chased down, chewed up, and spit out by late-war rides, this would have to be a very well planned mission complete with a sizeable fighter escort for the P40 "heavies" in order to have any remote prospect of completing our task.