Shermans are certainly a complicated issue. Since I think of PG systemically, then layer on the Vassal presentation, singular answers become nigh impossible. Not that this hasn't happened before, Japanese Type 3 tanks, Soviet 76.2 field guns, and now 100mm artillery. The Shermans are just the latest headache.
Somewhat reiterating
what I said on Consim, I am leaning toward 2 versions for every Sherman. For Shermans 1943 and before, the default version having an armor of 3. This would cover the U.S. Army ETO 1942-43 OOB extension, and the 2 British desert OOB extensions. 1944 and onward would have a default armor of 4, except for the U.S. Army PTO 1942-45 OOB extension and the USMC OOB extensions. I am not sure what to do with the Soviet Sherman, I think it is a combination of the M4A2 and M4A4.
My thinking on that is that Shermans were continually improved in small ways, and surviving older tanks were often retrofitted. The M4A1 had thicker hull armor. Then M4A2 went back to the original glacis armor thickness, but was better sloped, thick turret armor and had a diesel engine. The M4A3, which became the standard American version, introduced wet storage and better arranged (though not generally thicker) armor, but some of the sub-series went back to a gasoline engine. The M4A4, standard export version, was largely M4A3, but with a diesel engine.
That leaves me the notion that by 1944, many M4/M4A1/M4A2 Shermans have gotten refitted ammo storage and good number have gotten A3 turrets. I have come across evidence for both situations occurring, separately and in tandem, but have no real idea of what the actual refit number may be. That is how I am thinking about it.
