So, as a prototype, I took the Ćęjále and Laŕḁ́sa noun stems for "king," wana and bukås-, and came up with this history:
wana- < wa:na:- < (wa:ŋa:-) < wə:ŋa:s- < wɻ:ŋa:sa-
bukås- < bu:kås- < ----------|
Is that at all believable?
(Pronunciation note: pretty much like IPA, but å == open-o, Ć == ʧ, ŕ is tapped, and ę == e)
x-posted to conlangs