This is tough, but I will try.
Mark was a GREAT player. It is hard to compare, but I would say Mark was at about the same level as Tevin. I'm talking about Tevin in his prime...when he was dominating Milford and winning tournaments against Arriaga, Alberdi, etc. Tevin was a great player. Mark was athletic, maybe not as athletic as Tevin, but he was close. He was a strong thrower from both sides, and fast. He could kill a point. He was a complete player and his only weakness was also his greatest asset...his desire to win. He sometimes beat himself.
Mark was a better player than Roger. Mark would be in the lates in any post, wheras Roger was always in the 1,2,3. Roger didn't have a kill shot and that is what set him back compared to someone like Mark. Mark was better than Adam, who I only saw at Miami when Milford closed. HE was a good player, good left side, left side rebote, but didn't have the speed or right side that Mark had.
I never saw Randy. I thought Randy was an early-middle gamer at the big frontons, I could be wrong. Mark was a late gamer against a very good roster. I only saw Benny as a backcourter, can't help you out with the rest of the FL guys.
Someone mentioned his brother Paul in the American backcourter thread. Let me tell you, Paul (who we sadly also lost) was not in the same league as his brother.