Tell that to the French high command and they'll believe you! Heinz Guderian proved that Armored divisions could work indepentantly and smash through infantry lines and utilize their mobility to flank enemy troops. When Germany invaded France they had 2.200 armored vehicles versus 4000 of the allies and the Allies tanks had better caliber cannons and thicker armor. The allies on the other hand belived that tanks should be spread among the infantry. Which tactic worked better?