"Not sure if Marcus could have done anything to save himself once tribes were reshuffled."

That's just it: He waited until the tribes were reshuffled to do anything. In this game, you have to play all angles. Putting 3 votes on Susie and then letting her hang was dumb. It would have been dumb even without the twist because a merge was coming. As leader, Marcus had the most to lose by ignoring Susie's needs. To make things worse, Marcus stupidly argued with Susie about the Corinne Incident.

I've played on-line Survivor games and, to be successful, you have to learn what the others want. Why did Susie have to spell out to Marcus that she wanted a F3 promise? Shouldn't Marcus have realized that she needed to feel she had a shot at the million and offered her a deal right off the bat? He should have even considered telling Susie that he would have taken her to the end instead of Bob, the bigger jury threat.

If Marcus didn't want to deal with Susie, then he should have made a Final 4 deal with Crystal AND Kenny. Marcus tried to settle TWO Tribal Councils instead of just the one. Dumb, especially since the merge had to be soon.