They have no role. Their design is terrible. They are superfluous in Soviet infantry design. Space holder in T1 for Shock Troops and Guards in the original design. Penalties have always blocked another infantry unit throughout the game:
- engineers with a flamethrower
- Guard with PTRS
- and meaning the legendary overlap of the Conscripts, the constant tug of war who is the main infantry, the constant interruption of each other, the constant requirements of the buff because one infantry unit replaces the other.
The best option would be to simply remove the Penals and not try to pervert to come up with a role for them, for them there is no one anyway. The Penalties will block other infantry.
Why dont pgrens or obers block grens and volks? Its because they have very different roles and until recently timing was far apart.
Penals only role is blowing up the occional bunker, provide early/soft at mostly without mg,s or atguns as support. Ow yeah and bleed you dry plus give a slow start.
It can work, but both being mid to close range doesnt help, both not having ai nades nor actual ai upgrade dont help as well. Both being minute 0 to 1 is not helping.
In the past they where the muscle where cons where glorified support and utility. Then they where nerfed and cons had to be buffed as a result.