I think this is an excellent idea. I still maintain that fields should be defended by a variety of guns - not just the dreaded 37mm sniper ack (ok, its not so sniper anymore - but its annoying as hell). Volume of fire should be increased, and accuracy decreased.
88's
37's
20's
small/large cal. machine guns. (quad .50's, 42's something)
(Psst - wanna add even more immersion? Include the historical tracer color for each round (except the 88's obviously))