They have it wrong.
British Mk IV.
T-34
M4 Sherman
T-55
M1 Abrams.
THe Mk IV was the first effective tank.
The M-4 Sherman, and, especially, the T-34 were two war-winning tanks. The Panther was the German attempt to copy the T-34 and does not belong on the list.
The T-55 was the first MBT and started the revolution that reached the current state with the M-1 Abrams series.
The M-1 Abrams series represents modern behemoths and is the current state of the art.
I thought two were the Hillary and the Reno.