Schreks, zooks, and piats can all be massed and they all perform better than PTRS rifles with way higher alpha strike potential.
And that is why they are more expensive
There is no reason why Penal upgraded with ptrs rifles should be terrible late game from a balance perspective.
Yes there. If one make PTRS good at late tank both Penal and Guards will be broken.
Penal will offer great early AI, Anti light capability and late AT capability and there will be no reason to use anything else.
Guards will will be able to fight most infatry and all vehicles.
Unit that can do everything efficiently are bad to diversity.
Penals are not badly designd.
Yes they are. Their semi elite status makes arrive to early and it has been attempted to balance them with long build time that does not work the same across game modes while they fail miserably in "anti light vehicles" role only to be frustrating for both user and opponent with their satchel charges and AT satchels charges.
They just need some tweeking. Your idea is worse. Cheap spammable infantry benefits are negated by having to build T1 first and T1 offers no support weapons to help you hold the ground you have taken.
That is they would have to be used with conscripts an offensive and defensive infatry.
And if you do not like this particular design there many other also.