Talking about the "use" of any new addition in the MA is just silly, nothing but most uber will be used. We have tons of planes that hardly ever get used in the MA because they are not an uber ride.
To those that say they aren't interested in history I ask just what are you interested in? This a WWII game/sim, which is based on ,gasp, history. Many of us are in the game ONLY for the history and could care less that some Russian/Brit/US plane can dominate the MA.
The M4 sherman was one of the most produced tank in WWII, and definately has a both a need and a right to be included in the game/sim. If for nothing else the senario folks, because no matter what gets added after new wears off no one will use it unless its UBER.
From a production stand point alot of the art work and balistic work has been done to make both the M4 and Pzkp III with the 50mm gun, the M4a2 with the 76mm gun could also be added without as much work as making an entirely NEW tank like the panther. The facts are that both the Tiger and the Panther and the Tiger II for that matter were badly designed for HP/weight which caused numberous tranny failures which we do not model in AH , the Tiger and Tiger II were so large and heavy that alot of roads and terrain were impassible them (also not modeled here).