And, too date, Israel (renaming them the Magach) and Turkey have already outdone the U.S. in the prolific use of M48/M60 Patton tanks in combat situations by a significant degree, each.
T-62's, T-72's, Centurion III's, and AMX-30's are easily the match of M60/M48 Pattons.
Technically, the T-62, early T-72, Centurion's, Leopard Is, M-48/M-60 series, and AMX-30 were all late model 'medium' tanks.
The M60A1 and T-64 were the first of the Main Battle Tanks, both having early forms of 'composite' non-steel armor and superior fire control systems (although still pretty primitive compared to developments since)
It's long overdue that Civ retire the old 'Modern Armor' unit in favor of the Main Battle Tank for the late Atomic Era, which was the start of major upgrades to armored units' mobility and firepower and protection/survivability.
And just a note on Supercarriers. In an Alternate Universe (like, say, one represented by virtually every Civ game) the first supercarrier would have been Japanese. The third super battleship of the Yamato class, the IJN Shinano, was converted while under construction into an aircraft carrier, and she would have weighed in at an estimated 72,000 tons fully loaded, making her by far the largest aircraft carrier built until the USS Forrestal of 1954.
In fact, in November 1944 while transferring from Yokosuka to Kure 10 days after launching, with civilian workers still on board, she was torpedoed and sunk by the USS Archerfish submarine. She remains the largest ship ever sunk by a submarine, a dubious distinction is ever there was one.
And yes, technically she was supposed to be completed as a 'support carrier', carrying extra ammunition, fuel and replacement aircraft (up to 120) for 'fleet' carriers, but she was being finished with a full size flight deck (armored) and hangar deck and so could have functioned as a massive fleet carrier if, by the time she would have been completed in 1945, any Japanese surface ship could stay afloat long enough to do anything.
