lvl.2 PPD-34/38(box) and KP/-31(box)
lvl.13 KV-1 and pz.4G
lvl.18 sniper SVT-38 and sniper G41
lvl.23 T-34E STZ and StuG III F/8
lvl.28 T-34 1941 and Finland KV-1B
Rather than mp28, which has a slow rate of fire, Suomi, a box magazine similar to ppd, would suit you better.
It is better to have body-increasing armor than the KV and No. 4 F2.
The Soviets had semi-automatic sniper rifles, and Germany should have a counterpart.
The StuG. 3 F/8 has better protection and guns than the StuG. 3 F.
The Finnish KV-1B will have weapons that fully correspond to the KV1.