My bad, I was looking at the graphs wrong, it's actually the other way around.
Did a simple test of each MG shooting at 21 clumped vet 3 Conscript models at around 30 range and got the following result:
Vickers > DSHK > MG42 > .50 > Maxim > MG34 in terms of how fast they killed all of them.
Doesn't say that much of course, because of how suppression works and other randomness factors, but I was still surprised to see the .50 perform worse than the MG42 which contradicts my ingame experience and to see the Maxim perform so poorly despite it having a good dps graph.
Might have to do it again but with the MG's firing against garrisoned squads so suppression isn't a factor.