What apprenticeship has he done? He's not coached a top flight seniors team yet, sans a few games when Ivan was crook and as a transition coach when they were already in the top four. His only actual coaching credentials are a NYC coach in the mid twenty teens. He's never had to struggle with a mediocre roster, or build from one.
Fiasco has spent time with Yank sporting organisations. Just because they've done it, doesn't mean they've taken anything from it.
If by hanging around a club where other coaches and execs have laid the ground work to be successful and riding the coattails of that success constitutes an apprenticeship, then yeah, he's had a nice long apprenticeship. As an actual coach though? Yeah, nah.