Even if you accept Ange has no responsibility for the injuries through his style of play, it's very hard to make a case that he hasn't managed his squad incredibly badly to the point of negligence. Not playing Spence for months and not picking him in the squad for EL, throwing VdV and Romero back in against Chelsea, his over-reliance on Solanke. I'd add his use of Reggie albeit I know there is a decent counter argument to that. That's fairly epic mismanagement of his resources in my opinion.
In my view, he's got to go. I'd love him to turn it around but I've absolutely no faith that he will and I strongly believe that the mess he has on his hands from an injury point of view is one that is at least partially and in my opinion, largely, of his own making. And that, in my view, is rank bad management before we even touch on results which are beyond unacceptable.