Saying the Sherman was the best tank of the war due to its ultimate effectiveness is like saying the Russian soldier was the best soldier of the war due to their ultimate effectiveness.
The point is, man for man, the German and American soldier was a better soldier one on one than the Russian. The Russian’s effectiveness came from the mead grinder mentality of throwing millions of them at the Germans. You can only kill so many people so fast and if they just keep coming, you eventually run out of ammo or get overrun. That is the effectiveness of the inferior Russian soldier.
That is basically what you are saying — that the Sherman tank is individually a better tank than the myriad German tanks just because we flooded battlefields with Shermans,
Tell that to all the tank crews who rode to their deaths in the Ronson Lighters or the Burning Graves. The strategy ultimately proved to be effective but tank for tank, the Sherman was quite mediocre stacked up against the body of German tanks.