I think there are enough differences between the G41 - G43, and the 33/40 - K98k to make each unique as far as gameplay is concerned.
The G41 was available in limited numbers beginning in spring of 1941 (1200 pre-production, evaluation, G41(W)-marked units delivered by July 2, 1941), so it shouldn't be very common even on early war maps. It reached peak production by late '42/early '43 until the factories began gearing up for G43 production instead. As long as map makers take that into concideration and limit the availability of the rifle, the G41 has every right to be in the game.
As to the rifle itself, it is heavy overall and specifically muzzle heavy. If added to the game, it should quickly fatigue the avatar's arm in unsupported positions. Perhaps the sprint distance could be decreased while carrying it as well. (It's my opinion that it should be decreased when carrying heavy guns like MG's and such.)
Additionally, it has a fixed magazine and was designed to be fed solely by stripper clips. This is a significant difference from the G43 and its detachable magazine design.
Both of those would make a big difference to game play relative to the G43.
Likewise, I feel that the 33/40, while not widely used would be a useful counterpart to the M38/M44 if appropriate for the units on the map. Take all the qualities of the Mosin carbines and apply them to the 33/40 and you have a fair rifle for use with Gebirgsjaeger units.
Just my thoughts.