For example:
Engineers and their utility
Conscripts with ppsh
m3
guards
shocks
maxim
at gun
t70
suchka
m5
katty
t34/85
is2
isu152
These units are strong and viaable , i dont think they underperform , only problem is kv8 overperforming not the other way.
Problem is half of those things are doctrinal.
Without doctrinal the list stands at
(Conscripts without ppsh)
M3
Maxim
At gun
T70
M5
Suchka
Katty
I'd argue mortar and su-85 could be added, with t-70 and katy needing minor buffs - t-70 to Stuart HP, katy revert aoe nerfs.
Of that list it's clear t1 has only the m3 as viable, which is viable only for the first half of the game.
T1 is a victim of the flawed design of the game on release - they wanted to have a similar matchup to wmq and barracks from vcoh, but had to reinvent because reasons.
Jeep became m3 with the ability to carry troops meant to be useful with the blizzard and deep snow mechanics. Rifles became t0 conscripts (really hate t0 "no decision necessary" access to basic inf), penals were put in instead. I've never liked penals, if I want ff I go engies, they have no late game upgrade and basically offer worse utility than conscripts. The only good thing added was sniper, but sniper has fallen out of favour.
They need to give t1 a useful core unit. A lot of people wanted penals removed and guards to be t1, but after the big sov tech reshuffle t3-t4 this died down a bit. I wouldn't want guards as they'd counter 222 too easily making t1 super strong. I'd love shocks to be added to t1, or at least some more utility such as ppsh upgrade available to conscripts at t1.
Edit autocorrect hates conscripts