When you watch the videos, it's easy to fall in love with his skills. His touch when dribbling is really incredible.
However, I think anybody that thinks he is a sure thing is kidding themselves. I would characterize him as high risk, high reward. He might absolutely be a monster player for us....like best midfielder in the PL kind of player. But he could also easily be a total bust. You never want to hear about a player that he was known for having a weak work ethic or for only showing up for big games, but both these charges have been leveled at Ndombele. It's not at all far-fetched to see him clashing with Poch.
If he buckles down and really puts in the work and meets the demands of the club that he come ready every practice session to train incredibly hard and every game to put in maximum effort, I think very good things will probably come. But it's a big if! And even then, you just never know, as discussed above with Soldado. Or a player like Aurier, where the concerns seemed to be 100% off the field and everybody assumed his on-the-field product would be fine....well his on-field product hasn't been great....he just wasn't the player we thought he was I guess.
So anyway, I'm excited for Ndombele. But I'm tempering my excitement with the knowledge that there's a very wide range of possible and even probably outcomes here.