Surely the common sense approach to stock management is not to spent thousands of man hours creating huge ditch and bank structures which you then periodically refill with clean material and the re-dig the ditch. The common sense approach would be to gather up a bunch of brushwood e.g. gorse and enclose an area that you want to pen your animal in. This would keep the animals in and the predators out.
Common sense would dictate that a circle isn't the most practical of shapes to choose as a stock pen. It's very difficult to catch a beast within a circular structure, corners are far more practical.
Surely a common sense approach would indicate that megalithic structures are not practical structures for day to day use. They involved a massive investment of time and labour - much more time than, for example, was invested in the building of houses and other domestic structures.
Then there is the archaeological evidence. Henges were not maintained as domestic structures. They were cleaned, maintained, they contain burials and objects and been placed within them. Henges have orientations and relationships with other monuments both natural and man-made.
None of this is a quest for spirtituality in the 21st century it is based on observation, excavation and common sense.