There was no such thing as a 'tanker' K98 either. There was a carbine made for mountain troops though.
Now write this out 100 times, "Armoured types do not and did not use rifles. There is no space in a tank for a rifle."
Well, I was a Sherman "tanker" back in the early to mid 60's and I know for a fact you're right from just a practical point of view.
I could never get that "freakin" FNC1 they made me qualify on through the turret CC cuploa, so they gave me a Sten SMG first, then quickly upgraded all of us to Sterling SMG's and Browning 9mm Hi-powers as personal weapons.
To be honest, I couldn't possibly see any kind of a carbine (even the M1) being issued to tankers. At least the Sterling's butt folded under and I could get it through the hatch, but still bashed by teeth on it most of the time.
Regards,
Badger