In the B-25C's defense, it's not a sitting duck all the time. It really depends... In the Krupp Steel practice frame my squadron of B-25Cs was low-level and literally ran headlong into an enemy squadron (an entire 12-plane squadron!) of Fw190F-8s!
We wiped them all out with 1 or 2 minor losses!
And, then again, the same thing happened during actual frames and we mostly got wiped out (a few surviving). Same planes, same groups of pilots each side, totally different results.
Ya never know how much you can withstand! I took so much damage from 3 Fw190s in a later frame I had half my parts missing and the fighters went RTB due to LACK OF AMMO! I limped home while me and my dorsal gunner marvelled at our bullet hole count in the airframe.
So don't let Shuffler there scare you off
