It's apparently a coading nightmare. I've asked for this before. If we had multiple gunners we cannot have slaved guns and to have both slaved guns and multiple gunners there's too much to figure out. Therefore bomber usage would drop like crazy. Although i want the return of the B-17 Deathstars too 
who cares about the coading, its only a wish. However the truth is we have a hard time getting
one gunner I dont think three as gonna happen. I want the deathstart back too, but it is wishful thinking

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semp