Ronaldo probably wanted to work on structions/formations that would best enhance his outputs/goals. Ralf he would have to design formations where others would have to do the running/pressing for Ronaldo. That would be a fraction point for a lot of teams since they have to carry his physical load and yet Ronaldo gets all the glory. This would explain why ETH insist on making sure he has the last word on transfers. Ronaldo wasn't Ole's choice like DVB.This is probably the biggest thing revealed so far, imo. It's the clique problem that destabilised Ole in the early season and ruined Rangnick in the late season.
I would guess that Pogba is the one who wanted 'enjoyment and fun'. And probably Ronaldo is the one who wanted formation work. They're easily the two biggest personalities in the squad, at any rate.
This probably explains why things went so badly after his signing. Not that I'm blaming Ronaldo. He'd be absolutely correct in wanting more structure to our training. But you can see why it would divide the dressing room and cause disharmony to spill over onto the pitch. For the rest of the players it would be like picking between mummy and daddy in a divorce.