Ken,
I would say sand capping is not so common at to be at any point in most design process thoughts. I think Tom D has stated he tried sand capping the approaches and chipping areas, including herringbone tile and now doesn't think it works? Sorry if I misremember that.
That said, in my experience, sand capping sometimes just transfers your problem down 4 to 6 inches. It certainly requires drainage in the clay layer to work.
I would also say that the perception of wet conditions due to overwatering is outdated by about 20 years. Most of the courses I know conserve irrigation, because of cost, or as per best practices in some cases to avoid further regulations, i.e., lower water use limits.