And the DPS charts from Relic's attribute editor states that these things are hardly more than a slight improvement/side-grade on a unit with very good weapons. The only place where the G43 performs more effectively is the 30-35 mark.
While they do have different damage models as the StG is an automatic with less damage per round and has burst while the G43 is single shot with less penalties while moving (no burst to be reduced), it's honestly not worth it in most causes. You generally don't want PGs to be fighting at max to begin with as that's what your Grenadiers will generally be doing along with the 42. You want those assault rifles to deal with approaching infantry who are getting into the mid-short range where most Ostheer units suffer.
Weapons with ranges set to: 0/10/15/20/25/30/35
PG G43: 12.8/9.6/6.87/5.22/4.2/3.5/3.0
PG StG 44: 15.35/12.8/10.1/7.69/5.4/3.38/1.44
That says everything. It's not worth. Buddy, can you check how it gonna work on stosstruppe with STG's with G43's and tactical assault? And without G43's? I'm courius how it can work with that great ability