I'm not going to review it, but as a note, I finished reading J.P. Mallory and Victor Mair's The Tarim Mummies last night. Again. It's actually one of my favorite non-fiction books; it delves into a mysterious pre-historic and para-historic mystery and although it comes up with a nice, plausible solution, it's careful to point out that it's far from a done deal.
The Tocharians, the enigmatic people who are the main focus of the books, are an interesting linguistic problem, and a good fit for the similar interesting archeological problem; what the heck was the Afanasevo culture doing so far to the east in the Minusinsk basin, when it looks like a transplanted Pontic steppes culture like the Yamna culture?
I know it's kinda silly, and possibly ethnocentric in a bad way, but I can't help feeling a kind of kinship with these far-flung peoples who spoke languages similar to mine (kinda) and who seem to have the same Eneolithic cultural ancestors (if not actual genetic ancestors). They seem like extremely early pioneers, not unlike our own pioneers who settled the American West... except that they were three or four thousand years earlier and they went east from the Black Sea to the Altai Mountains and the Tarim Basin, not west to the New world, and from there to the Great Basin.
Still... you gotta work with what you've got.