^^^
I think that puppchen is going to be pretty important. I'm guessing that its performance and cost will be lower than both Zis and Pak. Cost is probably going to be in the range of HMG/mortar but more than the 45mm AT gun (200 MP)
Its penetration is going to be around that of the panzershreck, and its range/accuracy is going to be better.
Around 3? by the time T-34s/Sherman 75s start spamming will probably be what the OKW will be needing.
Panzershreck: 180 max penetration, 120 damage. Range: 35
My guess:
Puppchen: 180 max pen, 120 damage, Range: 50
Sherman apparently has 480 health,with sherman jumbo 640.