Penals are quite capable of dealing with light vehicles, and shred infantry. Their satchel charges are potent and require care as well.
The maxim is a straight upgrade to the conscript squad right now. You get a script squad, but with suppression, why wouldn't you always pick this unit up?
MGs are supposed to be static units that you fight around not paired or tripled up.
The changes I see are a good attempt at addressing a real problem, Maxims are too good and cannot be balanced in their current form without making them feel unresponsive.
Maxim may be too good, but i rather have an Hmg42 from T0 anytime instead. (with armor piercing in bonus).
My solution:
-Pack faster then now, must have the time to pack upon getting a flaming nade, or hit from a mortar);
-Get out of building faster then now;
-Suppress more, but less than an mg42;
-Do less damage, but more then an mg42;
-Cost more then now;
-Slower to setup then now;
-10% less firing arc than a Mg42 with same transversal speed.
-No Vet ability;
-Vet 1,2,3 close too the same bonus as the Mg42
Now you have a defensive HMG.
So no more spamming, but you got something durable for your investment. (Soviet style)
But it won't solve the anemic soviet offense...