I've seen you consistantly make these claims. Do you have any credible source that says smaller tanks were symptoms of smaller engines as opposed to the other way? Or that the breech on the 125mm was unnescissarily large compared to ones used in other countries?
As for the smaller tanks and smaller engines thing...it's kind of obvious in tank design: if you have the engine to push more tank, then you build more tank.
That's why the Soviets ended up with some ungodly big monsters at the end of the WWII, and why Brits were powering the Centurion with a derivative of the Hurricane's engine.
The Soviets do that to. You read the quote: they found out the West had a different size gun, so they immediately slapped a larger one on their current tank almost as a kneejerk reaction.
At any rate, it is clear from the performance you get that less crew is better, which is why so many countries, have gone that way, with their new tanks, not just ex-soviet ones, but Countries like ROK, Japan, France. If you look at the best new and upcoming tanks that are being introduced today such as the Type 10, Oplot-M, and K2 they all have decided to go with the 3 man crew.
Those are countries with a history of quality engineering. I still wouldn't take an autoloader over a manual loader, but I'd trust a Japanese or French one over a Russian one. You don't hear horror stories about French ones.
If you look at the original design specifications for the T-34, you can see that they designed it with these wopping tolerances: +/- .039 of an inch in most cases. I'm a machinst, and we can eyeball that. What the Soviets built their tank industry towards coming out of WWII was making simple designs that could be built by reasonably untrained labour with low quality control. And for the T-34, T-54, and T-55, it worked great. Then something happened around the time of the T-64: they started putting heavy mechanical equipment on it that requires good quality control, but didn't enact any.
I've seen this a million times where I work: they sacrificed quality for quantity, then tried to turn on a dime and expect the opposite. Then they were surprised when it ripped their arm off.
On the other hand, the US army is currently scratching its head over how they're going to trim 15 tons off the M1 for the next upgrade.
Hey, I'm the one who wanted the M8 AGS. Me personally, I think the L7 105mm could've stayed on every tank we have and still made every creditted US tank kill since 1991.