Hard disagree. What the Ukraine war has shown is that NATO tactics (and tactics attempting to emulate NATO, i.e. the initial Russian push) don't work against opponents who are sufficiently armed and entrenched. You have to go back to literal WWII block and push tactics, but also mix in electronic warfare and drones.

NK is more than sufficiently armed, and their general strategy, which will likely be to blow the hell out of Seoul, doesn't require them to move any of their artillery or bunkers, and still has no real counter outside of preemptive bunker busters, which SK does not have nearly enough of to destroy those emplacements. They would likely have a difficult time ever advancing on SK, but it is more than within their power to stalemate any aggression that comes towards them. The only way that doesn't happen is if the majority of the NK military literally breaks and runs. Which could happen, but there isn't anywhere for them to go.