In this case I meant slow to the point where it's a genuine problem in Tielemans and Neves, unless you're talking about signing someone who can play the last 30 minutes when Eriksen sits and also just not play and have Fred or Sabitzer in there when you think the midfield will have big gaps and the lines between attack and defence won't be tight.
De Jong isn't really a quick decision maker, he's just got that thing Messi and a lot of the greats have where he can beat players who are stationary or at a bad angle and can change the tempo and progress the ball based on where the gaps are around him.
Sort of like Lisandro does at CB, where it's not that his decisions are shockingly fast, it's that he understands space and how to build up and his feet are just really good (He'd probably be my first choice for the world 7 a side a LCB I think, though that's a whole different thread and De Jong would be an interesting discussion as the CM in that setup, with Enzo, Rodri and Kimmich all reasonable choices too) though it looks totally different. But their ability to change the tempo from fast to slow and slow to fast,(which maybe is that whole pausa thing everyone is always going on about) is not dissimilar and I think Ten Hag really likes it?
