For once, I sort of agree with a transfer-related opinion of yours.
It's not that Tielemans and Winks are exactly equal in their development and potential, as much as it is that Winks simply fills the same role that Tielemans does, is home-grown (and a Spurs lads to boot), is enormously talented himself and is already immersed in the league and English football more broadly.
Maybe Tielemans is a little bit further along in his development and potential than Winks is - doesn't really make the trade-off worthwhile for me, though. We have Winks. Tielemans would be a waste. If we need a CM, I'd prefer one that more directly mimics Dembele's playing style and physical attributes.