Kamara is a defensive player with good passing, Luiz is a creative playmaker, McGinn is a workhorse, Ramsey is a ball carrier. They all play completely different roles.
I agree that he is different to all the above, but he's not as good as any of them at what they do which makes him at best a bench warmer, and Chelsea will be looking for 40m for him, which would be a complete waste.
He's mediocre at best.