I disagree fundamentally on what we need in the attacking third then. We need more players like Lamela (and Mason/Bentaleb) that move the ball quickly to pull opponents out of their shape, not players that hold on to the ball long enough for the opponents to regroup and find their shape.
We've seen Dembele a lot. He's never looked an integral part of a fluid attacking Tottenham. He's been the solid defensively, hard working, athletic type that made us solid - but ultimately reliant on individual stars to create our chances or score a large portion of our goals through sheer individual brilliance.
Thought Lamela and Dier did well on the right against City, or in Lamela's case "from the right". Lamela didn't move inside too early all that often, he helped create the space for Dier to move into. When he got on the ball moving inside he naturally got it on his stronger left foot, which wouldn't be the case for Eriksen or Chadli playing out there.