That one is the key issue here. Lamela has already shown how to properly serve Defoe and for him it should be irrelevant who's playing upfront between Defoe and Soldado.
As long as Townsend are unable to make something out of his eternal dribbles, either hitting the target or passing the ball once in a while, then Lamela should be given time to settle into the team.
Lamela is a typical counter player. Good pace, strong dribbler and lethal when cutting inside. He is also a capable playmaker which should complement Tottenham's possession style as well.
Unless the team starts to score at least twice as often, they will struggle immensely this season. It's tiring for the players to iron out one goal wins after another.
I hope they start to gel soon, this squad has potential all over the place.