Russia claims 500 according the are article Ukraine claims 12k. I tend to think the number is more than 500 but 12k seems a bit high.
I dunno about that. I’ve seen videos of long columns just decimated.
one thing I do know, Russia has neither the military nor the money to occupy Ukraine for long. And whatever government Russia puts in place if they even get to that point, would never last. This is a major problem for the Putin regime.