Jose Mourinho is overrated as a manager and not the best ever as some claim.
Why? Stick him at a team where they're not already dominant or allowed to spend and he'll struggle. Is he a very good manager? Yes, but he's incredibly overrated. I hate it when people say he's the best ever.
Paisley, Ferguson and Busby were all better than Mourinho. In my honest opinion, his biggest achievement was winning the CL with Inter Milan because Serie A teams at the time were being criticised for slowly falling behind (the fiascos etc.) and his tactics in those games were amazing.
Does he have the potential to be one of the best ever? Yes. Is he now? Hell no. People need to calm down.
To be fair, it is usually only plastic Chelsea fans who come out with this tripe though but I guess I should let them off as most of them believe football only started when Mourinho took them over the first time.
As much as I loathe Manchester United, there is no doubting Ferguson is the greatest of all time. For me then, second spot goes to Paisley. Although, if anyone argued Paisley was better I wouldn't argue back because that's a fair argument depending on how much you value domestic/european honours etc.