i know this has been talked about before but i still think and champion that the M4A3 Sherman should have the option aside from having an armor upgrade to increase durability to include a 76mm gun upgrade (via MU or FU costs) to increase its offensive capability. with the way warspoils are working right now its very difficult or unpredictable to get the pershing or easy 8 commander and you may have to spend money to buy them which some people cannot afford it. so having this option available non-doctrinally in my opinion should provide a flexible response for those who dont have either of the two.
top is the 75mm variant: the default sherman for the USF medium armor
upgrade it to the 76mm gun and you get this