HEHEHE, Jim said "Antedates" HEHEHE
On the FG42, it was NOT intended as a BAR type of weapon. It was intended to give every soldier a single type of weapon to perform the duties normally given to weapons like the K98, Burp Guns, and the LMG's then in service. This would, in theory, result in a simplified logistical chain and greater firepower for light infantry.
The FG42 weighed LESS than the StG44! It was in the same weight class as the M-1 Garand and. The BAR far outweighed them. For a 10 pound gun with the same capabilities as the BAR, that's quite a feat. Even the excellent Johnson LMG outweighed it by three pounds. The fact that the FG42 was not fielded in greater numbers was good for our side to be sure. What-if's are not fair, though, as the FG42 was more expensive to produce and unproven at the time of its initial issue at which time Germany was being relatively successful with other guns. WHy change?
As to the K-98, it was only the 'backbone' of the German army in terms of numbers. Tactical doctrine, however, was that the Machine-guns were the primary weapons around which squads were built. Hitler himself acknowledged this with his efforts to hault further rifle production. There were quite enough Mausers out there, thank you.