I posted the same message about if buddhism preceeded hinduism in another forum and a buddhist replied with this:
'The word Hinduism was coined by the Muslim scholar Alberuni in the 11th century C.E. and while its appropriateness to describe the dominant system of religious belief in the India of his time (and of ours) is unquestionable, its use to describe the oldest religious beliefs in India (some scholars even applying the term to describe the pre-Aryan civilization represented by the Harappan culture), is clearly suspect. In this respect the practice of the earlier scholars to use the term "brahmanism" to designate the system which prevailed amongst the Aryan invaders before the Buddha's time, and to confine the word "Hinduism" to designate the system which was synthesised in the Bhagavadgîta, a work compiled centuries after the Buddha, which became the foundation of almost the whole of later Hinduism, could be commended. This terminology will be used here as far as possible, except that the word "Hinduism" will sometimes have to be used to designate the combined systems of Brahmanism and Hinduism proper, the actual context hopefully making clear what usage is meant.
The question of chronology has usually been considered a difficult one. Many students of Hinduism after proclaiming the impossibility of ascribing dates to early Brahmanical works, then not only proceed to do so, but give them very ancient ones with little or no justification. This is true not only of Hindu traditionalists, but also of many Western orientalists, who in the words of Nirud C. Chauduri "have succumbed to Hindu chronological fantasies" [Hinduism (1979), p.33]. It may be mentioned that the antiquity claimed for the Hindu texts contrasts strongly with the lateness of all extant epigraphcial, iconographical and archelogical evidence. In contrast to this morass of uncertainty the dates of the Buddha (563 - 483 BCE) have been established with little or no error. In fact the Buddha is perhaps the first truly historical figure to emerge in India, just as the Buddhist remains are the earliest religious archeological evidence unearthed. And the earliest Buddhist literature contain abundant information on the rival systems of belief prevalent in the India of that time. These references cover both the main Brahmanical religion based on the Vedas, and the emerging dissentient views proclaimed by the new sramana philosopher-teachers of the time (the "gymnosophists" of the later Greek observers of the Indian scene).'
I do not know what to think of all this or if i shall think anything about it