John - I am sorry - I don't mean to flood your site, but I have a bit to give. It might start off some serious discussions. :-)
The Mure family had cadets in three lines - 1) Mure of Caldwell (regarded as the senior line). 2) Mure of Rowallen (just north of Kilmarnock) Elizabeth Mure who married Robert II of Scotland was of this family. 3) Mure of Cowdams - now spelled Coudham (just South-West of Kilmarnock on the Kilmarnock-Ayr road).
The late Mrs Lesley Gordon was convinced that the families were inter-related and regarded each other as kith and kin. Whether the Caldwell's were followers of the Mure's or whether they kept themselves quite separate is a matter of conjecture. They certainly were not as wealthy as the Mure family. I have seen it speculated that the Mure family were the wealthiest family in Scotland at one time.
The notion of the highland clan structure and followers of a chief seems foreign to the south-west who were more of the nature of small "bonnet-lairds" with only a few retainers who helped on the farm.