It depends on the situation. While Carlo did well with what he had, Rijkaard had one of the best squads in the world when he won the Champions League. The reason why the latter won was IMO primarily due to the talent in the squad, not the coaching. Ancelotti also had a fantastic squad at his disposal, but I do give him credit for the way he got them together in Europe.
I suppose the best pure manager would be the one who can take whatever he's given and run with it, winning with what he has at his disposal. Managers such as those are very difficult to find. However, in my opinion, managers should be given the task of finding the footballers he wants to build the team he wants. Afterall, it's the manager's side. So the way Cloughie told the people above him to "sod off" so that he could formulate the team on his own was priceless and good for football in my view.
I did not always believe in Rikjaard's tactics but you have got to give the guy credit for sporting and then nurturing the talents of Messi, Iniesta, Krkic etc.
Yes he had a good squad but he was able to make then work as a unit with the help of Ten cate.
The reason I do not want to name my top managers is because with managers , you just don't know how much they really input unlike players where most things are visible.
I watching a documentary on West Germany on ESPN classic the other day and did you know that Helmut Schon had a nervous breakdown after West Germany lost to East Germany and it was Franz Beckenbauer that picked the team and tactics from then onwards in 1974 where they won the world cup?
Even with Rinus Michels, you do wonder between he and Cruyff, as to who used to pick the team and tactics.
Roy Keane blasted Carlos Querioz as he accused him of picking the way United played even if Fergie got all the praise.
It is very difficult to pump so much money into a club and not have any input at all as to what players you would like to see in your club; leaving all the decisions to a manager.
Clough was in an era when football was a sport and not a business and by the time football started to boom in England, he got Forest relegated in his last season.
Also Forest are not a big team so he couldmore or less get away with that as per telling the board where they could stick it
At Leeds after 45 days, they showed his ass the door as there was not a chance that he could get away with what he did at Derby County and Forest at Leeds United.
I have to say though that what Wenger has done at Arsenal with the budget he works within is absolutely phenomenal