He didn't have one way of playing. It also helped that he knew what he wanted in his team and how to implement it. Earlier on he was the coach. It's only later that he got good competent coaches for the tactical side of things
I still think he didn't win enough in Europe to be the best ever. In the UK, certainly yes.
Who would you have as the best ever?
It's a subjective question, I think what metrics one uses will determine their choice. Their success, influence on the game, innovation, longevity etc.
For me personally, Ferguson is the greatest manager of all time. There are other managers who I think influenced the game more in terms of the tactical side of the game, or some who adopted certain philosophies and elevated them to their peak. The likes of Cruyff, Sacchi, Michels and plenty more.
The reason Ferguson is my choice, is down to his incredible tangible success, his ability to adapt, and his ridiculous longevity. Football changed so much throughout his tenure as a manager, and he wasn't just able to keep up but actually dominate. He had a brilliant eye for noticing the trends in the game, and had the nous to both identify and apply these methods, as well as the management ability to know exactly who he needed to achieve this, both on and off the pitch. The ability to rejuvenate his team and create new ones as cycles came to a close was also a fantastic achievement. Most managers have a limited shelf life at one club, things become stale, players don't respond the same way and fatigue sets in. Ferguson was able to deal with all of this through his presence and clever management moves. Adding quality to his squad after a title win to keep everyone on their toes, changing staff through the cycles, ensuring that the respect from players remained high.
Add on the 49 trophies and managing in 5 different decades and he's my choice.