So in AoS, the Horned Rat rose to take his place among the Chaos Gods, completing an alignment process that was already in the works in Warhammer Fantasy for a long time. But lets suppose that the Horned Rat was merely absorbed by the other Chaos Gods and thus they became the patrons of the Skaven race. Now, which of the major Clans do you suppose would align themselves to which Gods?
Some of them are easy to match, like for example obviously Clan Pestilens would align itself with Nurgle, but where would the others go. Where would the assassins of Clan Eshin go, or the tinkerers of Clan Skryre?