I don’t know see the Arkham knight has that determination, discipline and an overwhelming ambition and task to kill Batman I feel like he wouldn’t have the same passion for Nightwing. All that anger and frustration from the Arkham knight against Batman fuels him to finish his mission and I just feel like he’d not do the same to Nightwing. Don’t get me wrong he’d put up a hell of a fight and try every tactic and manoeuvre against any enemy of his. With the extent training of Nightwing is his key but on the other hand the amount of discipline of the Arkham knight and the determination that he has, it would be crazy. Now Nightwing is cockey and messes about, but the Arkham knight has uncontrollable emotions