The way I see it, of those players you mentioned there are only three that do their best work from a wide position.... Son, Moura and Lamela. Zaha is better than Lamela, considerably so IMO, so is first reserve straight away. He has also shown more in the PL than Moura has (although I accept that Moura hasn't been here long). Son will also miss some games to play for Korea and there will be injury and loss of form over the season.
I think you underrate Zaha by a great deal. If he came to Spurs all of our attacking players would be wary that he is, at the very least, a proper challenger for his place in the team.
It seems as though Pochettino has been trying a 4-3-3 this summer. In that formation Eriksen will definitely drop back and I think Ali may do the same. It would leave us picking three from: Kane, Son, Zaha (what a front 3 that is!) Llorente, Moura and Lamela. 2 players for each position, which should allow us to challenge across all competitions.
Our options for the 3 midfielders behind them are then Ali, Dembele, Dier, Eriksen, Sissoko, Wanyama, Winks. This time 7 players for 3 places..... probably one too many in normal circumstances but considering Wanyama and Winks are currently injured and Demeble's general injury record that is probably a sensible number for competition and cover.