you can make it work and people are using it at almost every rank, but the inconsistency kills it.
I like HMG34, despite people hating on it a lot. In 2v2 I built it every game.
If I put all HMGs in descending orders my picks would be HMG42, DShKa, HMG34, .50cal, Vickers and the last would be Maxim for sure. The first two are excellent, 34 and .50 are good, Vickers is OK and Maxim is meh.
The DSHK better be good considering that one pays 300 manpower for it
yet it is comparable at best with the mg-42, which is 40 manpower cheaper.
I think that both the Dshk and maxim would benefit from a larger firing arc, both can be pretty easily flanked without even flanking the rear, but by just walking around the mg.
clearly the maxim strats simply work better on the MG-42, as the larger cone of fire and basically immediate suppression (eventually vet 1 ability) are really good, and it's weaknesses are the same for every other machine gun. The maxim gets to beat the mg-42 in green to green cover, apparently, but that is not exactly their purpose anyhow