At the risk of getting into a level of detail that's over your head (i.e. any), Valdano and Burruchaga were decent, but that's pretty much it. And Napoli were really nothing special. Pretty much every authority agrees on Maradona's ability to drag unpromising teams to levels of achievement they'd never have got near without him. This makes him unique in the pantheon of greats. After all, Cruyff had a great side around him, as did Pele and Messi has had the same. Maradona stands out by his ability to achieve great things without that support.
You may dispute his greatness all you like, but history bears this out.