Ignoring how stupid it would be to give 4x IR STG...
While you can't compare 1 model using IR STG vs LMG34, the end result is that it will be stronger and way more versatile than the LMG34.
You PRACTICALLY don't sacrifice long range dmg, for obscene close and mid dmg. It also mostly ignores accuracy modifiers from cover, including garrison (0.9 vs 0.5 normally).
More than 20m,2x IRstg44 ober can't defeat single mg34 ober even they in heavy cover shot each other,of course IRstg44 is powerful weapon,but Ober is long range shooter,and they are expensive to refinement,they on field timing they will face light even medium armor,so I think most time IRstg44 is worst than MG34 because you need send ober more close to enemy to keep the efficiency
Now in summer patch they will make Ober arrive earlier,but no weapon upgrade ober is not good,IRstg44 is used a commander ability slot and only for ober didn't like USF 1919LMG can be used by any infantry,I think allowed Ober upgrade IRstg44 without Panzer Authorization is reasonable