I have talked about Cimmerians in some other threads, as I said I am a historian and I don't care what nationalists say, there is absolutely no evidence which shows Persians lived in Iran before the arrival of Cimmerians in the 8th century BC, it is clear who established Parsua kingdom in the northwest of Iran, destroyed Ellipi kingdom and conquered Anshan (Persia), ...
I strongly believe that sound changes didn't happen in languages without any reason, there are some important reasons for these changes, like phonology of native languages, it is possible that for example "d" is changed to "t" in two different languages in two different places but when we talk about a group of different sound changes, especially in different places of articulation, it is difficult to believe there is no relation between them.
Are there any onomastic surveys of the West Iranian core area? Who lived in the northerncentral plateau and Balochistan before the Iranics came?