"The sacrifice of horses, in fact, is in no way specific to Vedic India: only the ritual of this sacrifice is, very different from that of the funerary ritual of Sintashta. The Indian aśvamedha is in no way a funeral ritual. Likewise, that the i-e name (?) of the chariot (ratha) is only attested in the i-ir languages does not mean that it is an i-ir invention, because, like so many others words, its equivalent may have disappeared from other languages i-e and because having a word to designate the war chariot does not mean that they invented it."
January 1, 1970
https://en.wikiquote.org/wiki/G%C3%A9rard_Fussman