I see what you mean but in fairness to McKennie he has been brilliant at Juve so could well have done that with us. I think the best example here would be Lemina - he arrived with a bigger reputation (and price tag!) than Diallo and fits your description down to a tee... EGO.
Don’t always trust Wikipedia, Sangaré has been an important first team player for PSV this season: https://www.transfermarkt.co.uk/ibrahim-sangare/leistungsdaten/spieler/375885 which is good, because it means our scouts did well to find all three options in the summer.