I never played the campaign.
I find Shock troops and penal squad designs to be muddled. I'd like it like this:
Assault Engineer: 6 man squad with ppsh, 1 flamethrower 60 muni, satchel charge, mine sweeper
Soviet veteran infantry: 6 man squad with SVTs, DPs, smoke, molotov, AT grenade
Penal Squad: 6 man squad with mosin, molotov, multiple grenade throws (like AG), multiple AT nade throws.
Of course, all will have appropriate costs, require munitions or teching.
The idea with my penal squad is to use them to do suicidal things like attack P4s or infantry blobs with close contact. They only have mosins, and have to rely on explosives tossing.
Soviet veteran infantry is the typical good tactical squad (comparable to US veteran infantry).
Shock Troops are Assault Engineers, also Penals should have been Frontoviki, I wish they were.
Also Frontoviki in campaign were misused, Frontoviki means "Veterans", but in campaign they're used as throwaway infantry. T1 Penals are more like Frontoviki since they are armed with SVT's and are better than Conscripts.