Your argument is predicated on wanting him gone at the end of the season (to be honest, would be nice to think he would) therefore would it not be sensible to bring in a defender to bolster the ranks. It's highly unlikely even Wenger can ruin a centre back in four months.
Unless your saying of course that Debuchy and Chambers have already been ruined beyond repair
Yes, give a well known alcoholic the company credit card whilst at the Christmas party. Brilliant.
But again you agree that the signings he has made haven't been poor, they have just become poor with poor training and poor tactical deployment (Wengeritis I call it)
My point is that we need numbers at the back, that should secure top four and leaves a good platform when in our world of wishful thinking Wenger sods off in May.