Chelsea already have have Hakim Ziyech joining them this summer, we know that for sure. SO rather than thinking about potential new players, we can look at one who is actually coming and think about how he will fit in.
On Sky Sports when the deal was announced they had a segment on The Debate with Tony Pulis and Kevin Philips where they debated his potential to be a Premier League star.
As is often the case with these things there isn’t actually much of a debate. They both agree basically that he’s talented but will have to try and settle in a much tougher league.
You can see the full debate here: