I don’t know the Warcry lore, but Crows of Tzneetch?
The Warcry war bands are chaos god agnostic for the most part and follow the eight winds of magic rather than the four chaos gods.
From Warhammer Community on Corvus Cabal:
Hailing from the Realm of Shadow, the Corvus Cabal are masters of ambush and assassination who worship an aspect of Chaos that they call the Great Gatherer. They honour this foul deity through deadly hunts, stealing treasures from the corpses of their victims. Believing Archaon to be an avatar of the Gatherer, they seek to gain the favour of the Grand Marshal of the Apocalypse, and thus please their mysterious god…
Basically they like to swoop down on enemies and have a thing about gathering trophies for their “god” known as the great gatherer.