Marcello obviously has fantastic BJJ, and Carlsten disappointed after he was hyped as an Eddie Bravo black belt. But, I think Marcello will be beaten early by someone with good standup and TDD. One-dimensional guys like him and Maia and Leites are old guard (pun intended).
Not to mention he was also a former Pride fighter. I didn't know who he was and i heard he's known for his fight in the backstage where he choked out some dude in a triangle.