Francfort (1989) stresses this point: "Nothing allows us to dismiss the possibility that the Andronovians of Tazabagjab are the Indo-Iranians as much… - Henri-Paul Francfort

In short, apart from the time-space expectations, there is nothing in the archaeological material that could be taken as tags for tracing the Indo-Iranians/Indo-Aryans.

p 268 Henri-Paul Francfort. La civilisation de l'Oxus et les Indo-Iraniens et Indo-Aryens en Asie centrale. 2005, in: G. Fussman, J. Kellens, H.-P. Francfort, X. Tremblay, Aryas, Ariens et Iraniens en Asie centrale

Recent hypotheses connecting the Oxus civilization with the Indo- Iranians or the Indo-Aryans are of two kinds: the first consider the Oxus civilization as an emanation of the Indo-Iranians / Indo-Aryans (Sarianidi, Hiebert); the second hold that newcomers from the steppes succeeded the Oxus civilization (Kuzmina) or took possession of it (Parpola, Mallory). This wide uncertainty, which may appear surprising, is due to the fact that no trace of invasion is noticed on the ground, no cultural transformation is marked by the presence of archaeological material whose origin could be attributed to peripheral regions. Expressions like “elite dominance” or “infiltration,” despite their great evocative power, are nothing but rhetorical devices. They do not manage to mask our present inability to account for a supposed historical phenomenon. [...] In neither of the two regions, steppes and oases, do we find an archaeological material that could be indisputably attributed to Indo-Iranians, Indo- Aryans, or Iranians.