Um, the Jumbo historically could be penned by panthers, raktens, ect. It will be almost impervious though to stugs and P4s
76mm upgrade requires you to go T4 to get the 75mm shermans to upgrade. 76 shermans can be a staple or a filler. Who says they have to be one or the other just because they're a staple with Soviets?
You are kidding, right? Are we even playing the same game? The E8 runs over raketenwerfers, and challenges the panther. It also demolishes the rest. You are saying that the Sherman jumbo, a sherman that would have a 76 mm gun, and even more armor than the e8 would have a problem with panthers and raketenwerfers? Sure. I was imagining it costing 190-230 fuel because of how tough it would be.
75mm Shermans are ONLY in T4. What you said about the upgrade requirement didnt have to be written. It would be a staple because you are making the standard tank badass. You fit 3 amazing aspects in one commander, when divided they can make 3 unique commanders. One commander being 76 shermans, one involving jumbos, and one, if Relic lies, the Pershing. But the Pershing did nothing for the war. Shermans deserve the spotlight. There are still a-ways to do with Shermans, and they provide more support to the overall theme of the faction.
A 75mm Jumbo (or the lack of the 76mm cannon on one) kind of sounds lackluster and reminds me of the 105 m4 sherman... why settle for less, sherman-wise, when you can have a battle tank capable of taking on heavies?