I think Spurs' first-choice midfield will eventually be a 3 of Ndombele/Winks/GLC, with Winks as the most central/deepest player. Ndombele and GLC are both excellent tacklers/pressers who can cover lots of ground in addition to their on-ball skills, so you can get away with playing a more possession-oriented deep third mid like Winks rather than a more physical defensive player like Sissoko and Dier. It will depend some on matchups though, and it's a little trickier if Poch wants to play a midfield 2, where I'm not sure there's enough defensive cover for Winks.
The bigger question in that 4-3-3 is how to pick just three attackers. Kane is obviously a shoo-in when fit, but that leaves Eriksen (if he stays), Dele, Son, Lucas, and Lamela competing for just two spots (probably IMO in that order). Plus Sessegnon, although I think he's more of a long-term project and it's unclear if he'll ultimately be used at left back or in a more attacking role. A nice problem to have.
One of the cool things about Spurs' business this summer is the youth. Ndbomele, GLC, Dele, and Winks are all 22/23. If they can keep the band together, that's a damn good midfield set up for the next 5+ years.