It is not easy to make a simple appeal to the Andronovo culture to resolve all the issues of Indo-Iranian origins... When the archaeological evidence… - James Patrick Mallory

The westward expansion of the Kurgan culture has been mapped with some degree of accuracy: “If an archaeologist is set the problem of examining the archaeological record for a cultural horizon that is both suitably early and of reasonable uniformity to postulate as the common prehistoric ancestor of the later Celtic, Germanic, Baltic, Slavic, and possibly some of the Indo-European languages of Italy, then the history of research indicates that the candidate will normally be the Corded Ware culture. At about 3200-2300 BC this Corded Ware horizon is sufficiently early to predate the emergence of any of the specific proto-languages. In addition, it is universally accepted as the common component if not the very basis of the later Bronze Age cultures that are specifically identified with the different proto-languages. Furthermore, its geographical distribution from Holland and Switzerland on the west across northern and central Europe to the upper Volga and middle Dniepr encompasses all those areas which [have been] assigned as the “homelands” of these European proto-languages.”

In his earlier works, Mallory himself, acknowledged that theories pertaining to an Asian homeland had long fallen out of repute, "but one wonders if this is not just partly due to the ridicule heaped upon them by their opponents rather than reasoned dismissal" ... "all too often has one discredited line of argument been used to ridicule another theory which came to the same conclusion" (Mallory 1975, 56).

Although [the domestic horse] has occasionally been recovered from Harappan sites, for example Surkotada and Kalibangan, no one would credit the earlier Harappan culture as exemplifying the horse-centred culture of the Vedic Aryans.