Don't know much about Lamela, but the general consensus was that he was a top talent. It's still early to write him off, I think.
I actually think that, with the exception of Soldado, Spurs bought quite well in the summer; and their failure to integrate all of them shouldn't really be taken as vindication of the argument that its wrong to sell your best players at their peak value.
It really depends on the circumstances. I think what Spurs did with their resources was pretty good - good young talent spread across different positions.They need a manager who can bring the best out of them; I don't know if Sherwood is the guy - I really haven't watched them much this season. But Lloris, Chiriches, Vertonghen, Capoue, Paulinho, Dembele and Eriksen are actually pretty good players, and that'd make a solid core if someone wants to build around them. In Bentaleb, Rose and Townsend, they have some good young talent as well - so there's scope for someone to do with them what we've done with Henderson, Sterling and Flanagan.
They've suffered more from poor management on the pitch than from in the boardroom. The only obvious error was Soldado, whose signing had major red flags anyway.
And for all their struggles, they're still not far from 4th at all.
Good young talent on the face of it, but unlike our Brendan, not enough thought gone into character/mentality. They're devoid of leaders in that side.