What he did at Aberdeen was exceptional in winning trophies from the Glasgow clubs. Ferguson spent big at United but he also successfully integrated academy players into the first team and turned them into world class players. Something Guardiola hasn't done And until he does he will be dubbed as a 'chequebook manager' by many.
You are ignoring the timelines.
It was 5 years before Ferguson bought through the family man, the first of the truly class players (if terrible human being) that he brought through from the youth team.
This is Peps 5th season and he has already brought through Foden.