StuG III A should be BR1 ( has same armor as Panzer III J but no turret or MG)
StuG III F should be BR2 ( has the same armor as Panzer III J but again no turret or MG)
Dicker Max should be BR3 ( has worse armor than Panzer III J and no turret or MG)
Jagdpanzer IV/L70 should be BR4 ( has same armor as Panther but no turret weak spot cuz having no turret)
Tiger E should be BR4 ( has worse armor and penetration than Panther)
SU-76M should be BR2 ( has no armor or MG)
SU 85M should be removed and replaced with regular SU 85 with less armor and then be put into BR3
IS 1 should be BR 4 ( useless in BR5)
IS 2 should be BR 4 ( same armor as Panther but overall somewhat worse gun )
SU 100 should be BR 4 ( no MG no turret )
M10 GMC should be BR 3 ( no coax MG and overall comparable to regular Sherman)
M18 GMC should be BR 3 ( no armor at all )
M4A2 (76) W should be BR 4 ( practically the same vehicle as M4A1 (76) W)
Sherman IC Firefly should be BR 4 ( performs the same as 76mm Shermans)
Chi-Nu should be BR 3 ( has the same armor as Panzer III J)
Na-To should be BR 3 ( has no armor no turret and no MG)
+future possible vehicles:
M36 Jackson → BR4
Pershing → BR5
Comet → BR4
Churchill VII → BR4
Churchill VII AVRE → BR5
Stug III G → BR3 ( has a coax MG)
Brumbär → BR4 ( rather strong armor and 150mm HE canon )
Ferdinant → BR5 ( stronger total armor than Tiger II H but very obvious weakspot, also no MG )
Sd.Kfz 222 → BR1
Marder III → BR2
KV 2 → BR 3 ( same armor as KV 1, but very long reload but great HE gun)
SU-122 → BR 2
ISU 152 → BR 5 ( hopefully good functioning HE )
IS 3 → BR 5 ( soviets need something to compete with Tiger II H)