I was a tank gunnery instructor at FT. Knox after my return from Vietnam as a tank commander on an M48A3 MBT, Tanks and M113 ACAVs provided excellent service as infantry support on the DMZ.
I spent much spare time in the Patton museum and was fascinated by the M4 cotroversy vis a vis German armor in WWII in NW Europe. You are mostly quite correct in your assesments, but the Brits installed their 17 pounder high velocity anti-tank gun into the M4. The bore diameter is close to the US 76MM, but the shot is heavier and delivers much more kinetic energy than did the US gun which fired the M93 HVAP shot anti tank round (APCR-T) The Sherman crews had to be within 300 yds of a Panther to assure frontal armor penetration with that gun.
The 17 pounder firing the SVDS round would penetrate over 6” of armor at 30 degrees of obliquity at 2000 yards, 7” at 1500 yards and over 8” at 500 yards, sufficient to crack the frontal glacis plate of a Mark V Panther most of the time.
The US put off plans to regun their inventory of M4s due to the M36 Tank Destroyers and the M26 Pershings coming on line with 90MM guns with even better performance than the 17 pounder.
I was stationed at Ayers Kaserne in Germany, 13th Cavalry, later changed to the 32nd Armor. we had M48A1s, they had the cupola but still had the gas engine. In the summer of 1961 I helped take delivery of some of the first M60s, very similar to the M48, better range finder, nicer gun.
We had a company of M103s and another of M41 Bulldog light tanks on our post also.The infantry had VTRs built on the M4 chassis . Our infantry companies received the new PCs before I left there and we got one of the new VTRs when we got the M60s. Our old VTR was an M51 but I can't recall what the new one was named. We didn't like it, the engine placement made it a bitch to drive on snow and ice, it kept wanting to spin out.
I was a Turret Mechanic.