If I only can choose one weapon, it has to be the Stg44... Because it is easier to handle than the BAR... This doesn´t matter very much on longer ranges, when fired upon, you simply hit the ground... But on short ranges, it doesnt matter if you hit the ground... You have to eliminate your opponent faster than he is able to eliminate you... Thats where the Stg44 has its edge...
The BAR, while being a great weapon, had a few shortcomings that was not a problem in themselvs, but together they made the weapon less than ideal.
-Weight: Actually very light for a machinegun of its era, but unfortunately too heavy as an assaultrifle.
-Capacity: Only 20rds is too little for a machinegun, but okay for an assaultrifle.
-No QCB: BAD in the SF-role, but okay in the assault-role.
The BAR was neither machinegun nor assaultrifle, but was used as both.
The easiest way to make the BAR more "machinegun", would be to simply turn the mechanism upside down, and create a "Bren-style" BAR with the ability to use 30rd magazines.
In stead of adding a QCB, simply more BARs should be added to the units, like the Marines did, with three BARs per squad, instead of only one like the Army did.