Consider the following:
Penal builds trade combined arms for raw early game power. They don't have mortars to push you out of fortified positions, neither mgs to control blobs. Axis factions will always have the tools to combined arms. That's one thing you can use.
Light vehicle play give penal build trouble because how subpar ptrs penals are compared to actual AT units. You can actually chase damaged units into the base with 222s, luchs or flametracks. It forces soviets it into guard doctrines, which turns manpower into an issue if you are able to inflict cassualties.
A) How does 160 Manpower and 20 Fuel lock you out of t2.
B) How is being forced into a guard doctrine a downside? Are any Guard Doctrines lacking in any particular aspect?