I think the M4 (Or what ever it is) should be used with the police, as well as the MPK, the MPK can be in the back of police cars and used when in a gun fight, however only pistols should be used. The M4 can be given to NCA and AR to keep in their cars for operations and quick responding.
Rebels should get the 5.56 variant of the AK I think, as well as maybe the Mk20 and TRG, however no scopes bigger than the MRCO, because snipers aren't really fun, however there should be a threat of getting robbed, but not as much as on Altis. Should be the way you play that determines this
However a move towards pistols rather than large guns is good imo