Please tell me how Soviet .50 Quad is balance against 251 AA HT.
Quad is better in every way and cheaper.
251AAHT Smoke is worth absolutely nothing against non braindead players who can attack ground. It should not have to pack up to move, which is the other thing I forget to mention, besides having to be stationary to fire, it has a delay or setup/pack up.
Attack ground is a non-accuracy shot and is less likely to hit than just shooting a unit within your ATG/Tank's sight, so the smoke forces you to have a toss-up whether or not it will actually get destroyed.
And why should the OKW FHT have more health compared to other AA units? It's fine as is.