I'm less concerned about NK troops and more to do with the weaponry they'll be providing. When was the last time NK was involved in a war?
Are they well resourced and trained? If anything, apart from the bravado and possible desire to get stuck in (if professionals), they'll be fairly green.
It'll be interesting to see how, if used on the front line, they'll be integrated into the chain of command, because I can't see them being autonomous.
So will Russia use them wisely, or will they be more cannon fodder? The rounds, shells, drones and missiles are more of a concern.