I have some sympathy with your "not ritual again " view and undoubtedly claims for archaeoastronomy are overstated . Whilst accepting that the builders of the monuments had to have a mental life apart from their cosmology I believe that the emphasis on a ritual /functional distinction is a post 20 th. C. luxury . I havn't seen any of the previous threads so will keep quiet on what I think would have been obvious points regarding effort and obvious ritual at the bigger monuments.
One distinguishing features of the recumbent stone circles is that the stones are graded in height shortest to the N.E. tallest to the S..W this feature is almost certainly derived from the Clava cairns which also have graded stone circles encircling a graded kerb . Recent excavation (1994-96) has shown that the cairns and the circles were built with the final form envisaged from the start . This leaves us with roughly 2 metres between the circle and the cairns for the corralled animals . The reason for mentioning this is more to do with a circle you think may fit the bill for a corral than point out the weaknesses of the argument.
Meikle Findowie is an ellipse and has the same grading of stones as the RSC's and Clava Cairns as well as having an inner kerbed cairn (reported in 1909 also graded and now gone) Hardly ideal for providing stable footing This echoes the Clava cairns and suggests a lot of non-utilitarian thinking has gone into the architecture.
When you have cattle rubbing against stone as you would in a corral the stones develop a very distinctive patina . Balkemback stone circle has had cattle rubbing against for at least a century and is a good example but Meikle Findowie which has plenty of sheep in the area doesn't . We don't know the reasons for building stone circles and I would happily accept that there are stone circles in the record that were originally built as corrals , although I don't know of any but I wouldn't then accept them as stone circles merely circles of stone .