Easy 4th is British Challenger 2 MBT. Only downfalls are that it is slow and cumbersome, rifled barrel is actually slightly less accurate and less powerful than the smooth bore guns on the Leopard and Abrams (on tanks the round is already fast enough [mach 4 and faster] that is does not need rifling, and rifling actually has the opposite effect on most tanks compared with smooth bore main guns of the same caliber), vulnerable to IEDs without its expensive upgraded armor package, weaker and slower engine package and because of its heavy weight it also gets less driving range than Leopard/Abrams/T-90.
https://www.youtube.com/watch?v=Ic8Elgce7a8 