You'd need to take the Shermans' 45-degree defense out of the way for that lone Tiger to begin to have a chance! Even so he would need to knock out 2-3 of the Shermans (in medium 5 hits/tank) before the Shermans close down the 19 meter gap between the Tiger's effective gun range and the Shermans'. After that it becomes a hit point slugfest which the Tiger would lose because of its slow rate of fire. Those odds and scenario are based on well-documented history, and you'd need to do likewise for every type of tank. For example, how many StuGs are equivalent to one King Tiger? Or, how does a Sherman 76mm compare to a Firefly to a 105mm to a M51?

The game would be more realistic, for sure, but exceedingly complex. And if we were getting into realism, who would want to be in a Ronson to be one-shot killed by a Tiger 30 seconds into the game?