i dont think US needs more armour pershing is already fine and E8 jumbo wont be even that special imo
What are you talking about?
1. Commander we are talking about doesnt have access to pershing.
2. Its not "e8 jumbo", its M4A3E2 "Jumbo".
3. It would be very special, if it was somewhere between KV1 and Churchill this would be unit type USF has no access to.
Best thing would be to slap some special skin on it (or existing skin in different color), limit it to one and make it buildable from major tech, similar to OKW tiger.