It's been striking how all recent managers have been fans of DCL (Koeman, Allardyce, Silva, Ferguson). You get the impression that he's great in training and has the right attitude. As a result he's been given the chances.
Contrast that with a player the same age in Ademola Lookman, who a lot of folks on here were more excited about. He didn't get into the team, was ultimately let go, and now can't get into the Leipzig team.
There's so much that we don't get to see as fans, and it's interesting with these two players that their performances/attitudes outside of first-team matches must have been markedly different for repeated managers to draw the same conclusions.