Maybe replacing Wenger with Emery and him still playing Xhaka and not sorting out the defence is part of the experiment
This club has a bit of a history with making bad decisions, maybe this is just the latest in a long line.
With Allegri not in a job at the moment, I'd personally be trying everything to get him in and get rid of Emery. Yes sure it would be good to give him until the end of the season, but if there's noone decent available when we get rid of him then, we'll end up with another Emery, better to get a proven replacement when he's available IMO.