Just a re-post from the training forum:
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I often wonder why we got the Ostwind in AH instead of the Wirbelwind, which was simply an earlier Ostwind with 4 20mm Flak 38 cannons instead of one 37mm Flak 43.
In reality, the Germans found that the Ostwind's single 37mm was a more effective AA platform than the 20mm's, largely because the 37 mm had much better range. The numbers support their assertion, and the Ostwind WAS a more lethal weapon, in the real war.
But, in AH, most people can't hit a thing with it, and personally I think 4 20mm cannons with a total RPM of about 800-900 (3200 rounds in total) would be more effective in defending an object like an airstrip from vulchers.
Then again, perhaps HTC decided they might be a little too effective at short ranges, given their heavy armor, and went with the M16 option instead, which is somewhat equivalent but with a glass jaw.