Yeah, but the T-34 had a lot more armor, and it was well-sloped. No variant of the M4 was particularly well-armored, so it dosen't matter in my opinion what the armor was on any of the Sherman models. But the early Shermans not only had low-velocity guns, but they also were equipped with poor-quality ammunition that sometimes shattered on impact. So, maybe try a 1945 scenario with early-model American tanks vs. Russian ones and see what happens.
