I think itīs time to give the Squadleaders their SMGs back...
The SL have to play like a assault class. He smoke the enemy line and lead his squad into the enemy lines, before he do that he could mark some artillery targets for the Commander, when possible.
But the rifle is no SL weapon, and a P38 or TT33 is nice, but no replacement for a MP40 or PPsh41.
SMGs are good weapon, but it will be no over powered weapon if the SL can use it, too.
And if you thing 4 SMGs more are to much, why itīs not possible to reduce the slots for SLs?
1 Commander, 3 SLs (maybe only 2) are enough to lead 28 soldiers.
1 Comander for all, and 1 SL for ca. 9 soldiers. (when the server is running with 64 Player online)
Itīs possible in this mode calles realism, so it is possible to bring it back into the classic mode, too

give it a try.
SL is a very unpopular class in classic right now, no one will take it, some people choose rifleman befor they take the SL class (donīt ask me why).
And if there are only noobs playing SL or TL, you can talk to them (or start a kick vote - last option, of course)