Any reason why Gouffran has adjusted better than Marveuax? Simple - better attitude.
I'm not saying Marveuax is some sort of trouble maker, because clearly there's no evidence of that, it's just that Gouffran has more desire to succeed here. Marveuax lacks desires and it's so obvious in the way he plays. Unfortunately for us and for him, he's not that good to be able to make it with that attitude.