how long did it take SAF at United to win his first title and then win in Europe?
Football back then was fiercely competitive as a whole so you can't really compare it with today's version. Also Ferguson took a United team which was far from what it is today in terms of the magnitude of the club. You can say they were not a giant back then and Ferguson transformed them into one. So that in itself is very impressive, but it is totally different to Conte's situation at Juve. He inherited a Juve side after two average seasons, but in an average league and then won that league undefeated. But it was still Juve, whereas Man U in the 80's were not the Man U you know. Let's not forget that Ferguson had achieved European success with a small side like Aberdeen before he took the United job.
Still, Ferguson has always been a bit overrated imo.