Ukraine

It's a good question what "loss" means here. A total disorganized rout is also a total loss, even though some men might be recoverable and still in fighting shape. The hardware is cooked though. And actually, a rout usually means the Ukrainians get to capture it, so there's your new tank.

And I wouldn't want to be the guy trying to find where hundreds of North Koreans ended up near Kursk, with them not speaking any language anyone would understand and not knowing the area.

The Kursk front has some of the biggest single hits the Ukrainians have delivered to Russian manpower though. Remember the troop convoys where artillery hits were killing dozens to hundreds of soldiers all at once since the freshly mobilized troops didn't know where to go and were just sitting densely packed in trucks on the road?