This is a map of Ayrshire by John Strawhorn
It shows the main villages & towns plus the districts of Ayrshire. The districts' boundaries are rivers:
North to south Irvine, Ayr, Doon
The districts are possibly the areas held by sub-kings in the days of Strathclyde.
In the days about the time of David I of Scotland the most principal barons of each area were the progenitor's of the Stewarts in Renfrew (immediately to the north of Ayrshire) and Kyle Stewart. The de Morville's in Cunninghame. King's Kyle was held directly by the king and Carrick was relatively lawless.