There's a lot of truth to that. They had superior, higher performance, but less reliable and less numerous, tanks, as compared to the U.S. and Soviet models.
Actually the Russian t-34 was superior to most German tanks in more than quality. It could kill the panther out to about 1000 K and could hold its own with the Tiger, it is considered to be the best Tank in WWII. The Tiger was sent to Russia in order to stem the T-34 tide. T-34s were built fast and cheap but with great armor and a excellent gun. Our M4 was very reliable and fast to build and a good thing too!!