Not surer that Onomah is overrated. He's probably rated about right for what he's shown against people in the same age group. He's dominated youth football. The 'problem' with him is that his playing style doesn't easily translate against the bigger bodies and better athletes in men's football. Where he was probably bigger and stronger in the youth game and could brush aside players similar to the way that Dembele does, he can't do the same against men. I suspect that we'll see a massive improvement in his game as he grows into his body a bit more, spends some time in the gym and physically matures. I'm not writing him off just yet.