Carbines worked like that since forever in CoH...You're arguing real life. I'm arguing reality of the game series.
I just don't personally think that "it's always been like that" is a good argument for something to continue being like that. Say, for example, CoH has always implemented the Bazooka as a weapon that you use against other infantry squads like it's Call of Duty or something, and since it's so effective at anti-infantry, they made it so that it's really bad against vehicles to compensate. Then, since they needed something to perform well against vehicles, they gave the riflemen a grenade slingshot upgrade that they can use against tanks.
So, the game is definitely balanced; the bazooka is a good anti infantry weapon that's bad against tanks to compensate, and then riflemen have a good anti-tank weapon if they need it. It makes sense in the game, and in this hypothetical it's always been that way, since CoH 1 even. Does it make sense though? Does it need to be that way? Not really.
Point of the absurd hypothetical is just to say that just because something is the status quo, it isn't necessarily the best way of doing things.
Although I said I wouldn't come in here to talk balance, I do want to say that I like the idea of the M1 carbines being some kind of MP44 equivalent. Realistically, I think that it would be fine if they just slowed down the RPM of DAK panzergrens' K98s (visual change only). If you do that, then M1 Carbine is more of an outlier compared to the other mainline weapons.
Maybe, just maybe, if there was some kind of M2 Carbine upgrade (like NaOCl mentioned), then the paratroopers would have access to some kind of "fire superiority" type ability that lets them use their M1s to their fullest potential.
Just for comparison;
Rapid firing a K98
Rapid firing an M1 Carbine
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