Marner 100 times out of 100. Mitch has his faults, but flopping around like a fish ain't one of them.
I think people misconstrue why so many are okay with him moving on... for me, mainly it is about the team cap structure. Sure, his attitude comes off as obnoxious or whatever, but I don't think he is that way, and I do think he cares probably more than anyone in that room, too much sometimes to the point that he cripples himself.
I think it has been proven that 4 top heavy forwards do not get it done, so one has to go. Won't be 34, won't be 91. I think Marner is probably better than Nylander, in fact I am sure of it, but you can only pay one of them imo as that cap money needs to feed the rest of the lineup (defence especially). I think the team gets more of a return for Marner. If, at the end of the day Nylander is the one that goes, I think the team is in a better position... Tre has himself a full blown dilemma!