For me the biggest reservation with Campo would be the ability to make the transition from assistant to senior coach. We've seen blokes likes Sanderson fail to do exactly that.
As an assistant you get to have a very different relationship with the players to what a senior coach does. At the end of the day, all of the tough decisions come back to the senior coach. Sanderson tried to be both mates with the players and bloke to make the tough calls. He ended up doing both poorly.
I reckon its possible to do by changing clubs and coming in as a senior coach but I reckon it would take some exceptional people skill to do it at one club.
this reservation would sureley apply to all current Assistant coaches with the aspiration to be a senior coach
IMO the next 3-4 months is a real audition period for Campo