Although that's no different to a manger taking over mid season...a good example of this is Pulis.
Good managers and coaches should be able to adapt their team's style of play based on what they have at their disposal.
He's only a footballer trying to earn a living and can hardly be called a turncoat when Poyet wasn't going to offer him a new contract!
Anyway as last seasons leading scorer in the championship - what a no brainer.