I will throw my suggestions here from my mod and then toss my reasoning (also you didn't happen to steal some of my numbers, did you?
):
-SVT accuracy to .7/.65/.55
-SVT damage from 8 to 10.
-Cooldowns and aim-times adjusted.
-Squad cost increased to 300 manpower and 27 reinforce from 270 manpower and 22 reinforce.
-Reinforce time from 4.5 to 5.4. Build time from 27 to 32 seconds.
-Flamethrower Upgrade now adds 3 PPsh-41s to better mesh with the flamethrower.
-Flamethrower cost from 60 to 90 and renamed Assault Package.
-Population from 7 to 8.
-Reduced the drop-rate of the Flamethrower to 10% from 33% due to the PPsH-41s that are added to the squad which are considered slot items.
-"Tripwire Flare" changed to "To The Last Man!" This ability is a passive that increases the power of the squad as they lose members. Modifiers are +4% accuracy, -2% weapon cooldown and -3% received accuracy per member lost.
Their DPS from 0/10/20/30/35 is 5.81/4.5/2.9/2/1.8.
Why such powerful early weapons? Because T1 is a dedicated AI tier. If it'll have the crippling flaw of lacking actual AT it should provide powerful units which also means less linear teching and choices for the player, even if T1 and T2 aren't expensive at all.
Why the increase in reinforce, build, and cost? Cost is obvious since they're better than most squad in direct combat early on. Reinforce is so the Soviet player can't spam Penals without being punished unlike Conscripts. Build-time is also to give player more time to capture the map against T1 openings where an early Penal unit would counter anything that's not an MG or a Sturmpioneer flank around the corner. It also meshes well with Conscripts who can be used to keep costs down who would also be screening for this unit.
Why the swap to PPsH-41s to mesh with the flamer? We all know that rifle turned out horrible because the USF squad was not only durable, but they had weapons that would chew you up at most ranges the moment you left cover. If you kept the new SVTs you'd have a similar situation, though obviously without the power of smoke or grenades. Furthermore, it means a role change for Penals which is something we need ie: trade-offs. Do you try to maintain them as an effective range squad or do you go in close where you're not durable, but will be able to deal lots of damage. Finally it means Penals act as a DPS unit for either range.
Why no improvements to received accuracy? It overlaps heavily with Conscripts who should be doing all the screening. It's been the role of Conscripts aside from their other utility roles. Besides, the high amount of accuracy bonuses for Penals would mean the scale just as well against infantry, but they shouldn't be forming the entire core of main line infantry.