Your totally right,if we had them in mass production and we would have been there first.
Our answers to the German Tiger II:T-28 and T-29
Primary armament: 105 mm Gun T5E1 on both.
The numerous types of Shermans made:
M4 Sherman Medium Tank
M4(75) Sherman I Medium Tank (Primary armament: 75 mm Gun M3)
M4A1(75) Sherman II Medium Tank (Primary armament: 75 mm Gun M3)
M4A2(75) Sherman III Medium Tank (Primary armament: 75 mm Gun M3)
M4A3(75) Sherman IV Medium Tank (Primary armament: 75 mm Gun M3)
M4A3(75)W Sherman IV Medium Tank (Primary armament: 75 mm Gun M3)
M4A3E2 Jumbo Assault Tank (Primary armament: 75 mm Gun M3)
M4A4(75) Sherman V Medium Tank (Primary armament: 75 mm Gun M3)
M4A5 RAM
M4A6(75) Sherman VI Medium Tank (Primary armament: 75 mm Gun M3)
M4A1(76)W Sherman IIA Medium Tank (Primary armament: 76 mm Gun M1A1, M1A1C or M1A2)
M4A1(76)W HVSS Sherman IIAY Medium Tank (Primary armament: 76 mm Gun M1A1, M1A1C or M1A2)
M4A2(76)W Sherman IIIA Medium Tank (Primary armament: 76 mm Gun M1A1, M1A1C or M1A2)
M4A2(76)W HVSS Sherman IIIAY Medium Tank (Primary armament: 76 mm Gun M1A1, M1A1C or M1A2)
M4A3(76)W Sherman IVA Medium Tank (Primary armament: 76 mm Gun M1A1, M1A1C or M1A2)
M4A3E8(76)W HVSS Sherman IVAY Medium Tank (Primary armament: 76 mm Gun M1A1, M1A1C or M1A2)
M4(105) Sherman IB Medium Tank (Primary armament: 105 mm Howitzer M4)
M4(105) HVSS Sherman IBY Medium Tank (Primary armament: 105 mm Howitzer M4)
M4A3(105) Sherman IVB Medium Tank (Primary armament: 105 mm Howitzer M4)
M4A3(105)HVSS Sherman IVBY Medium Tank (Primary armament: 105 mm Howitzer M4)
Sherman Firefly Cruiser Tank (Primary armament: 17-Pdr ROQF Gun Mark VII/VIII)
Info from:
http://panzervince.membres.jexiste.org/USArmor/index.htm