Not surprised. The T-34 and T-34-85 were superior to anything the US was building, at least until the M26 Pershing came along at the end of the war. The best feature of our tanks was that we built LOTS of them. A Sherman couldn't take on a Panther, but a dozen Shermans could.
The Brits called the Shermans “Ronsons”..as in the cigarette lighters..for obvious reasons..