Yak-9T - incredible firepower (or maybe incredible tank's lack of armor?)

[gaunt1]

Checked achtungpanzer.com

It turned out, the Pz.III should be tougher than the Pz.IV!

thickness/angle:

Pz.IIIH:
Turret Top / Bottom: 10/89
Upper Hull Top / Bottom: 17/77
Lower Hull Top / Bottom: 16/90

Pz.IIIL/M:
Turret Top / Bottom: 10/83
Upper Hull Top / Bottom: 18/79
Lower Hull Top / Bottom: 16/90

Pz.IVD:
Turret Top / Bottom: 10/83
Upper Hull Top / Bottom: 12/84
Lower Hull Top / Bottom: 10/90

Pz.IVG:
Turret Top / Bottom: 10/83
Upper Hull Top / Bottom: 12/85
Lower Hull Top / Bottom: 10/90

Starting from the H variant, turret top was reinforced.

StuG IIIA:
Top / Bottom Superstructure: 11/78-90 & 17/85
Top / Bottom Hull: 16/90

StuG IIIG:
Top / Bottom Superstructure: 11-11/75-90
Top / Bottom Hull: 16/90

I think all of them should be quite vulnerable to 30mm and above, but enough to stop 23mm, unless the aircraft dives on them vertically. (which is very unlikely)

For curiosity, the King Tiger:

Top / Bottom Turret: 40/78 / 40/90
Top / Bottom Superstructure: 40/90
Top / Bottom Hull: 40-25/90

Should be totally invulnerable. (except for the Hs-129B3)