To be a great manager, you need to know how to build a great football club and how to source and develop great players. Brian Clough knew these things. He turned unfashionable Nottingham Forest into European Champions by building a squad of largely unheralded players, getting them to believe in themselves and to play as a team.
Sir Alex learned much from Sir Matt that he was able to graft on what he had achieved at Aberdeen. He didn't just recruit a team to win Scottish titles and a great European competition; he built a dynasty.
He was recruited to Old Trafford because the man who was to become his mentor, Sir Matt (who also had great humility and personal generosity), recognised the same qualities as he had himself.
Sir Matt entrusted the legacy he had built to a man he believed could emulate him. Little did he dream that man would go on to eclipse him in such a mighty way.
Sir Alex has built a dynasty. That will make it both easy and hard for his successor to follow. Easy because there is a self-perpetuating machine in place; hard because they have to follow in the footsteps of the great man.
But like Sir Matt, Sir Alex will make it easy. He will be there when needed, but only when called upon.
This is why Pepe Guardiola would make such a great successor. He also knows how to build a dynasty and has similar personal qualities.
Sir Alex has taken the model and evolved it, to build generation after generation of great teams, not necessarily flooded with great or well-known individuals. Maybe Alan Pardew can do this at Newcastle. The signs are hopeful, so far.
So the first thing a manager can learn from Sir Alex is how to build a great football club.
Now you might say he had an unfair advantage in this respect, because United are so rich. But the misguided souls in green and gold scarves will tell you he has had no money since the Glazers took over—yet he's won 13 major trophies in those six years, including four and probably five Premier League titles. So that puts paid to that ridiculous claim.
United is now one of the two or three richest clubs in the world, but it wasn't when Fergie took over. They were so poor that three years later, Michael Knighton nearly succeeded in buying them for £20 million on borrowed money.
Ten years later, Rupert Murdoch bid £680 million; the Glazers paid £800 million in 2005; and United are now believed to be worth anything up to £1.6 billion.
And the biggest single factor in that has been Sir Alex. He built the squads; he achieved the success; he bolstered the brand; he attracted the supporters; he made United really great.
Football club management is a threatened art, mainly because of the move to the new model of coach and Director of Football. Harry Redknapp has it and Arsene Wenger excels in it, but the French professor of economy has not turned his business management into a trophy for eight years.
In truth, Sir Alex has David Gill alongside him, but they complement each other perfectly: Gill manages the business; Ferguson the football.
Yes, Sir Alex has his own idiosyncratic style, but even that has evolved over the years. He himself admits that he never stops learning, and that is the one overriding quality of a great manager and springs from humility.
Although he started life as a shop steward, it is arguable that he would have been successful in big business also. He knows how to set out a structure and build a football club from top to bottom and from bottom to top. He could write the MBA syllabus for football management.
There are many pieces to the jigsaw, however. He knows how to win the undying loyalty of the clubs' owners. He had it with Martin Edwards and also from the Glazers. The main reason why they are never seen at Old Trafford is because their investment is in safe hands.
They just leave Ferguson and Gill to get on with it. When the two of them ask the Glazers for something, they get it. It helps that David Gill is a world class chief executive. He has grown and grown with the club to its present £400 million turnover, dwarfing that of Chelsea and City.
Ferguson also understands the business and financial management. He is no mug. Some supporters think the Glazers won't give him money to spend on players, but his childhood gave him an appreciation of value, and he treasures the club's funds as if they were his own.
He is a master of economy. He has been the first to admit that he has made mistakes, like Eric Djemba-Djemba, who was pretty much disconnected from reality. But he also bought Chicharito for only £8 million and Eric Cantona for £1 million.
He will have a short, medium and long-term strategy. The short is each season; the medium will be the period taken to transition to the next generation; the long is his ultimate master-plan. Sadly, that will include his time of going and his successor.
It would not surprise me one jot if Sir Alex hasn't put forward two or even three potential successors, agreed with Gill and Sir Bobby Charlton. They will already be lined up and sworn to secrecy, which means it won't be Jose Mourinho (although he makes a convenient stalking horse).
My choice would be Pepe Guardiola to take over at any time; or a team of Carlo Ancelotti and Ole-Gunnar Solskjaer, with the latter groomed for succession after three years.
Although Sir Alex has teams of people to do everything, it is in his makeup that he would not ask anyone to do something he would not prepared to do himself. He does his own dirty work.
He will have personally told Berbatov he would not even make the bench for the Champions League Final; and also that he can leave at the end of the season. But as with so many players before him, that won't stop Dimitar from praising the boss before and after he goes.
Best of all, it is such a delight to see a manager writing his own programme notes. These are all written from the heart.
Also, he is constantly exhorting his "twelfth man" (the crowd) to support the team at difficult times. And they respond, as they did at Blackburn magnificently, and will for the rest of the season.In short, they love him.