When you look at where the early family is found it appears from the Doon valley to the south bank of the Irvine (or thereabouts) = Kings Kyle. It then appears relatively thin on the ground north of Kilmarnock to suddenly blossom in large numbers again in Southern Renfrew. This is the area of the early Stewart patrimony. The Mure's and Wallaces (and probably others) also seem to be so divided. Even in the same family they seem to have property around Kilmarnock/Ayr and further property north in the Paisley area. The lands under the influence of the Cunningham family run in between.
I will stand corrected by anyone who has studied this matter in greater detail.
I propose looking at the family blood feuds that went on in the area to get some idea if the Caldwell's were consistently allied with any particular side. From what I have seen it might be hard to get a pattern and I presume changing alliances.