crifice, as part of a formal cult?

Here are views diverse enough, but each has its advocate or advocates.
According to the earlier European writers the Vedic poets are
fountains of primitive thought, streams unsullied by any tributaries,
and in reading them one quaffs a fresh draught, the gush of
unsophisticated herdsmen, in whose religion there is to be seen a
childlike belief in natural phenomena as divine forces, over which
forces stands the Heaven-god as the highest power. So in 1869
Pfleiderer speaks of the "primeval childlike naive prayer" of Rig Veda
vi. 51. 5 ("Father sky, mother earth," etc.);[15] while Pictet, in his
work _Les Origines Indo-Europeennes_, maintains that the Aryans had a
primitive monotheism, although it was vague and rudimentary; for he
regards both Iranian dualism and Hindu polytheism as being
developments of one earlier monism (claiming that Iranian dualism is
really monotheistic). Pictet's argument is that the human mind must
have advanced from the simple to the complex! Even Roth believes in an
originally "supreme deity" of the Aryans.[16] Opposed to this, the
'naive' school of such older scholars as Roth, Mueller,[17] and
Grassmann, who see in the Rig Veda an ingenuous expression of
'primitive' ideas, stand the theories of Bergaigne, who interprets
everything allegorically; and of Pischel and Geldner, realists, whose
general opinions may thus be formulated: The poets of the Rig Veda are
not childlike and naive; they represent a comparatively late period of
culture, a society not only civilized, but even sophisticated; a mode
of thought philosophical and sceptical a religion not only ceremonious
but absolutely stereotyped. In regard to the Aryanhood of the hymns,
the stand taken by these latter critics, who renounce even Bergaigne's
slight hold on mythology, is that the Rig Veda is thoroughly Indic. It
is to be explained by the light of the formal Hindu ritualism, and
even by epic worldliness, its fresh factors being lewd gods, harlots,
and race-horses. Bloomfield, who does not go so far as this, claims
that the 'Vedic' age really is a Brahmanic age; that Vedic religion is
saturated with Brahmanic ideas and Brahmanic formalism, so that the
Rig Veda ought to be looked upon as made for the ritual, not the
ritual regarded as ancillary to the Rig Veda[18]. This scholar
maintains that there is scarcely any chronological distinction between
the hymns of the Rig Veda and the Br[=a]hmana, both for