the best tank is one that can kill all armoured threats with a single shot. Which is all of them.
the better crew with better C4ISR and a worse tank will kill a worse crew with a better tank.
In ukraine most tank engagements ive seen are below 1km and i have only seen a handful of tank vs tank engagements.
those tanks are fine, but if you use them like idiots and you crew sucks (which seems to be a thing with russians) you are in trouble, better to have them than not.