I often read "for every bad RNG roll you get a good one", "you only remember the bad ones", etc.
Lets be clear: Whilst RNG is equally applied to all tanks, it is far from being equally distributed.
Let me take the Leopard PTA as an example. A paper tank with a fabulous gun (view range, mobility are not affected by RNG, so not being discussed).
This tank has 71mm max armour. So even if every gun it faces maximum low rolls, virtually all shots will pen. Blocked is virtually always due to an auto bounce angle. RNG effect - negligible. Effect of removing RNG - virtually none.
Now its penetration: 268 average with a 201/335 spread. If facing a tank with 267 armour it will fail to pen approx 49% of the time. RNG effect - huge. Effect to removing RNG - (pen every time) so again huge.
The conclusion which therefore has to be drawn is that not only do heavily armoured tanks benefit from their effective armour over more lightly armoured counterparts , they also benefit disproportionately from RNG.