He doesn’t deserve credit for Derby. He deserves scorn. That Derby squad is one of the best the Championship has ever seen and they still fucked it up.
I thought your post was hyperbole so went to remind myself who was in Derby’s squad in 2019 - you’re right, they were utterly stacked for the level. Loads of solid Premier League players with a scattering of future stars. Waghorn, Marriott, Andy King, Curtis Davies, Joe Ledley, Bradley Johnson, Scott Carson, Martin Olsson etc. For the Championship, and looking at the table that year, they had a better squad than the two automatically promoted teams.