the only thing the penal needs is a buff to their rifleman and a vehicle snare on their satchel.
You may be onto something here: if Satchels can affect vehicles like the way UKF's Gammon Bomb does, it gives Penals a role in dealing with enemy vehicles without copying Conscript's AT snare; in fact it would make a good combo: use Penals to tank damage and try to stun with Satchel, and Conscripts meanwhile move in and snare the tank.
In other words: Satchel = stun, AT Grenade = snare. Any Soviet player is free to use either unit by itself to deal with tanks, but for best results you build T1 and get Penals to assist your Conscripts.