Yeah Luffy seems to be almost set in stone to face Kaido as soon as he is ready furthermore. I doubt King would capture him while they fought and on top of that it's even still vastly unsure whether or not Marco will even lose or resign the fight.
Oda will presumably portray Marco to defeat King or go close to it, in the latter case Zoro would probably jump in and ultimate the job. I don't see much ground for other scenarios at the present moment. Luffy will likely be busy with Kaido in the first place.