A lot of this discussion is irreverent guys, equipment ratios are dependent on what units we are simulating being involved. You standard infantry squad at the time period for the Germans and Russians basically had similar number of SMGs and LMGs, with the Soviets having a STV in there where as the German one probably did not have a G41 (since production was pretty small). You throw in a Panzer Grenadier units have more MG34s than a standard infantry squad and proably an extra SMG or two. You throw in a Russia assault unit, you get lots of PPSH's. Russian tank riding infantry tended to have lots of SMGs as well.
Reading Glantz's books on Stalingrad, it seems the Germans often led their attacks with an SMG company of sorts, or at least the Russians always describe the inital attackers as being armed heavily with SMGs. Follow up waves had your more standard loadouts.
There is a lot of variation, none of it is especially right or wrong. Custom maps are all based on what flavor people want, I think it would be cool to have a battle between a standard German squad and a Russian tank support team with PPSH's.
The only thing "wrong" with loadouts is G41 numbers IMO, probably should not be so many available as there are now. We definentally need more bolt action rifles.
As a regular template, it probably makes sense to give both sides (64 player):
3 Squad leaders (SMG only)
3 LMGs
3 Assault class (SMG only)
2 Elite riflemen (Semi Rifle or special unlock)
21 Rifles.
More "historically flavored"
German (tended to have more MGs available)
3 Squad leaders (SMG only)
4 LMGs
2 Assault class (SMG)
1 Semi automatic
21 rifles
Russian (tended to have more SMGs and semis available)
3 Squad leaders (SMG only)
3 LMGs
3 Assault classes
2 semi-autos
21 rifles