I don't think it requires great individuals. It requires individuals twice as good as their opponents, which is possible in Scotland but not in England even with unlimited funds. Ange simply cannot manage at this level.
There's no organization, or even attempt at organization, to the defending. Which is why we need to move on. Take the good of his attacking philosophy and marry it with the sound defence and quick recovery tactics of Iraola.
If you gave me control of Tottenham for 48 hours, I'd sack Ange, have Iraola name his price, and pay £80M to sign João Neves to a 5 year £200k/week deal.
I think we'd win the Europa League, and with a half decent summer we'd be right back in the mix next season.