Dennis..
They forgot the M4A6..and the M4A5
About a hundred of them made ...
Had a 75MM gun and a radial diesel(If you can believe that)..
I believe that Catapillar built them..
Only other diesel was the M4A2...
M4A6 - Diesel engine; composite cast/welded hull lengthened similarly to the M4A4; 75-mm gun only. Only a few dozen of this variant were built and none were used in combat.
M4A6 used the extended M4A4 hull with some modifications for the different engine. The radiator blister on the rear deck was round-cornered and lacked a radiator filler cap, which differentiates it from M4A4. There was also a bulge in the engine compartment floor to give the engine sufficient clearance. The M4A6 had a cast front upper hull similar to that of late model M4 tanks which were also built at Chrysler's Detroit Tank Arsenal. All M4A6s used the single-piece sharp-nosed final drive and differential housing, as well as large drivers' hatches and a travel lock for the 75mm gun. The hull ammunition racks had the usual applique armor welded overtop of them, but the turrets used in the M4A6 were of a later design and did not need reinforcing armor.
The designation of medium tank M4A5 was given to Canada's cruiser tank Ram II.