Liverpool deserve their lead. The problem with Spurs' 4-2-3-1 and this personnel is not enough distribution and passing options from deep. Liverpool's press are forcing Sanchez and Dier, etc. into tricky on-ball situations where they don't have great passing options. Even the better passers like Vertonghen and Eriksen are getting caught making mistakes where they have no easy passing options. They badly miss Alderweireld today; with him they could play 3-5-2 and have much easier passing triangles at the back.
The other problem with the 4-2-3-1 is that the fullbacks can't get forward as much. When the fullbacks can't get forward, the attack becomes very narrow. Eriksen, Son, Kane, Alli are all running the same channels. As a result Alli has had to come much deeper to find space. There is room to attack Liverpool wide because Liverpool's fullbacks have been very aggressive and don't have natural wide midfielders to cover for them, but Spurs have nobody to do that. As the commentary team keep pointing out, Spurs have been oddly reticent to play long balls in behind, even though they roasted Liverpool with that tactic at Wembley.
I'm not sure how to fix it. They could bring on Winks for Son, and drop Dier into a back 3, but then they lose even more pace up top.
The good news is besides the goal, which was sort of fluky, Liverpool have struggled to turn their advantage into real gilt-edged chances. If Spurs can make some adjustments and right the ship they can get something from this.