Looking at other manufacturers Sherman kits, such the New Heller 1/72" scale kit,UM's and DML's 1/72" scale Sherman kits,they all share similar features which allow those manufacturers to have variations in their kits with just a few part changes. For example, the small hatched M4 and M4A2 Sherman share the same upper hull. The only difference between them is the engine deck. Heller cast separate engine decks for their M4 and M4A2 kits,and use the same hull for both kits.
So, with a single hull, two separate engine decks,two separate rear lower hulls and exhausts, a M4 and a M4A2 could be made from one kit easily. And with the option for two separate upper glacius plates, a earlier direct vision M4 and M4A2 could be made.
So,FOUR different versions could be made from ONE kit, having variations to represent the countries of all Sherman users.
Also, a Sherman Firefly could be made from the M4/Sherman 1c kit.
Just a suggestion