I honestly think that the M10 belongs in Mechanized to support the fact that they are all about fast hitting lighter vehicles. The Sherman 76 would fit pretty well in Armor company and help it compete better against medium armor spam better than the M10.
The HE shell is actually a pretty cool ability thou, I like the idea of it but practically it's another munition sink for Armor company that doesn't necessarily need (Flamers, Arty Ability, Elite vehicle crews, competing with BARS and Zooks)
Yes but currently the 76 Sherman is tied with the regular Sherman dozer upgrade which overlaps with the 105 dozer in Armor.
So maybe it makes more sense for the E8 to be in Armored while the 105 goes in Rifle company, being that it is an infantry support tank.