Jim Norton joined an already established show and added virtually nothing other than easy access to funnier comedians

Wasn't Jim responsible for bringing in at least a half dozen of the Cellar crowd comics to the show? Not sure of the full stories but I think a lot of those Cellar comics were close friends with Jim and he was a primary factor in helping bring them into the fold, Patrice being one of them. Patrice and Colin and early Louis ck were always fucking with Jim in a way they never really fucked with Ant, and that's not to say how they viewed Opie.

Opie had a good eye for talent and knew to encourage the right ones, from my memory he was constantly pushing behind the scenes trying to get Patrice his own show (Cult of Black Phillip show) or get him involved in some show on the station during the mid-late 2000s. I think Opie's gravitation towards Carl Ruiz is a continuation of that, Carl is a pretty funny guy and Gregg's instincts honed in on that, however too little too late

Others will know more details of the comedy cellar crowd relationships from that era but I think a case can be made for Jimmy's role in the helping the XM era show by bringing his comic friends into the mix.