How do you go from implying USF has tons of AT options for dealing with the Panzer IV to there only being the M36?
A M4A3 with support from ATGs or bazookas can deal with a Panzer IV adequately enough, and as it is the close range penetration of the M4A3 is fine versus the Ostheer Panzer IV (fun fact, the M4A3 AP shots have more close range penetration than the 76mm AP profile proposed here) With veterancy things become more difficult, sure, but overall IMO the Panzer IV is not so much a reason for the M36 to be so powerful as is the Panther, which the M4A3 is hopelessly inadequate against.
In other word the M36 can be toned vs PzIV and it will not cause any problems. I can not disagree with that but others do.
(Fun fact most tank battle do not take place in range 0 and the suggestions it to increase far penetration by 20%...)
Ironically this proposal doesn't actually meet this requirement anyway as this new 76mm Sherman would do terribly versus the OKW Panzer IV or vet 2 Ostheer Panzer IV. The only major change is that in this world the USF roster has lost a major AI tool and generalist in the M4A3.
And open the way for specialized units like the 105mm which is completely overshadowed by M4A3 Sherman Dozer.
As I have explained the M4A3 is currently imo an excellent Tank that make the other versions of the Sherman less attractive. The proposed redesign make room for each versions of the Sherman to bring something different to the table.
But the questions remains what in your opinion would be good stat for Sherman to used vs mediums?