Nah, I think a lot of those players are mismanaged, pure and simple. He's not an outstanding defender, but he could do a functional job if they do defensive work.
The thing with Arsenal is if they win five games on the spin, everything's forgotten. The cup suited an agenda when they won it, now it's all about CL football. If they finish fourth Wenger will justify his position, if they don't, he'll leave IMO. Simple as that.
There is a good set of players at Arsenal, if ever they needed a proper manager who could instil discipline now would be the time.