Ferguson was definitely not clean a far as agents go, as per link.
He sold players when they did not go the way he wanted (especially when his son was involved), not always in uniteds best interest.
https://www.iol.co.za/capeargus/sport/how-fergies-son-got-a-fortune-533639
Not to mention the Bebe situation, which definitely was one big fraud.
https://www.theguardian.com/football/2012/may/10/portugese-police-manchester-united-bebe-transfer
https://bleacherreport.com/articles/2010594-the-top-5-football-conspiracy-theories
The absolute bollocks that was written on here when he was not very well was ridiculous, he was a bully and cheat in every shape and form and would do anything to win a football match, he fitted that club perfectly, both would fuck over anything and anyone to get that club any sort of advantage or to the advantage of him and his family.
Anyhow, sorry for going off topic and definitely not having a go at any posters in here, so will leave it there.