It make work in 1v1 but not in 3x3 or 4x4. Like RedT3rror said sniper + penal blob = lot men power. Squads come late on the field (high price) and you can't hold line with small forces.
For example day before yesterday i play sov on Steppes 4x4. On 4 minute mark OST have 3 HMG and OKW have 2 cubels and 3 volks. I may have 2 penal and 1 sniper team insteed of my 2 con, 2 maxims and forced to mass retreat. Yeah, ally sov can do 2 penal and 1 sniper too and this will still not enough. I mean: 4 pen + 2 snp vs 3 HMG + 2 cub + 3 volks? I don't think it will work.
Again JT and ele supporting panthers it insane amount of resources. I use stugs then play jager and pz.IV (or maybe ostwind if ally infantry is extra blobing) then play fort. armor to cover my elefant.
Sov are mediocre. USA is terrible in 4x4 and i have no idea how people play them. And UK is good in all except arty.
You don't need to shoot through all map. You need hold stars and fuel. German HTD do at.
That opening works good for me... I usually get an m3 scout car too and Hunt down the OKW trucks the satchel with penals. M3 also hard counters kubel with the high penetration main gun.
BO: t1 penal SC penal sniper/penal depending on the map and enemy.
Then go t3 double t70 if they went battlegroup or SU76 if the went mechanized.
Then tech t4 and spam katushya and mines. They'll dive your katty and lose their tanks while you bomb the battlegroup hq