^^^^+1
Yes, I think it does give tactical advantages and I also think that there should be door machine guns and machine guns for the pilot of copilot to go against another heli. We could make it an option like airstrikes and squads.
Something like this one, used in Vietnam War (transport w/ door guns):
Link:
http://en.m.wikipedia.org/wiki/Bell_UH-1_Iroquois