Marrone beat Louisville (Who beat up Florida) and West Virginia. Its not really about that though, its how he took a program that was in bad shape and had the heading in the right direction. Jim Harbaugh was only 29-21 at Stanford. Its a bout the man really, Marron is respected by many.
Is it the right hire? Who knows. No one knew Mike Smith, Mike Tomlin, and Mike McCarthy would be any good. Same with Philbin.
Sight unseen it's hard for him not to wind up an upgrade over Chan.