Why everybody think that these extra tracks on Sherman increase the armor
This is wrong, you can one shot with Faust and Schreck a Firefly on side (all Firefly got these kinds of tracks), ONLY extra armor on driver, tank leader and gunner place really add another armor resistance. Do test before to write that !!!
In real life the extra tracks was only a bad idea of allied tankers who thought that it could save their life, but it wasn't !!! In fact it was worst because all these splinters of steel could act as shrapnel into the tank in case of an impact.
Be sure of something to kill a Sherman, only avoid the armor plates and the front, other locations are one kill for sure.