Did you watch the Elite podcast video with Ole that was posted a lot here last week? It's an hour long, but a lot of good stuff.
In it Ole gets asked how much input others have, and he says something along the lines of that he respects other peoples opinions and he will listen to them, as long as they respect his decisions.
Like I said I think Carrick is more of a trainee like Giggs/Ole were after their playing career ended.
McKenna seems to be the tactician while Ole (mainly) and Phelan are the experience to "fact-check" the tactics when theory doesn't hold up against practice.
Ole was behaving like a coach while he was still a player. On the bench he would study the play to know what he should do if he comes on. Pretty sure he was allowed to give this info to the SAF coaching team as well, which probably has a lot to do with why Fergie wanted Ole on his team after player retirement.
Those who claim Ole doesn't know tactics don't know what they are talking about.
Sometimes, not changing anything is the right tactic, cause you can see that it has a good chance of working out over time by what chances we have in the games.
Someone else posted that Ole is the third best in the league to come away with points after coming under. Sometimes you gotta trust the prepared tactics work you did before the game, cause you don't have a super-sub you can put on.