In AH a 76mm Sherman will make the Panzer IV useless because they will have rougly the same AP/HE capability, same speed, and mobility while the Sherman will have vastly better AA defense. RL Sherman weaknesses like awful shilouette and terrible cross country and floatation will not exist in AH.
I suggest this.
A 75mm Sherman.
An 85mm T34.
As for German tanks being inferior to allied tanks before 1943 thats somewhat misleading. Most allied tanks lacked something truley neccesary for a succesful WW2 tank. The T34 had no radios, 2 man turret and no commanders vision cupola. The KV had no radios, a terrible turret crew layout with three crew but only effective as two men, and again no commanders cupola. All the French tanks had a one man turret, this made them almost useless operationally in WW2 battles. The British had too many tank types. The various Cruisers were too lightly armored and lacked good turret crews, the early churchill was an outdated near stepchild of WW1 with massive armor and weight but with a 2 pounder gun in the turret and a limited traverse howitzer in the hull. The Sherman appeared in late 1942 and fixed almost all those deficiencies, but by that time Germany allready had Panzer IV with L43 and L48 75mm and not to mention Tiger I which just entered combat.
But ever since Panzer III Germany had all those things a 5 man crew, radios, full vision cupolas, adequate armor, speed, mobility, and very good reliability to boot. Their greatest weakness was armament of 37mm or low velocity 75mm. The 37mm on Panzer III was soon replaced by a medium length 50mm and then by a very long 50mm that was prolly the equal of many 75mm. The Panzer IV got a longer 75mm L43 by the F2 model and then the awesome L48 late G models.
So you see German tanks were not all that at a disadvantage in actual battles. On paper yes they looked weaker, but battles were not fought on paper.