Tom Doak,
I never heard about draining greens 2 or 3 ways in landscape architecture classes. Architects like my mentor, and contractors like Wadsworth told me from day one that was a good idea. (Along with never draining water in a bunker, slopes onto a green, using any catch basin too close to the area you really need to drain, or letting overland flow cross a fairway, or letting water run more than about 250 feet (the distance it takes to concentrate from sheet flow to stream flow)
Over the years, I have seen architects vary from those rules, and maybe they are successful, but when I think I should be able to do it, too, they never seem to work out in practice. Whenever I drain all water off the front, including some surrounding mounds, the approach gets too wet. Whenever I drain a major portion of the green towards the cart path side that golfers enter, drainage and poor turf becomes an issue, etc. Say what you will, when I feel heat from the flame, I learn to back away. Ditto with breaking what those from 1950-1980 learned and took as standard practice.
I understand the notion of questioning standard practice, but there are some landscape architects believing its time to reintroduce American Elm to their landscape pallets, believing the old guys didn't know what they were doing. I believe they are short sighted. It is always about drainage, drainage, drainage.
As noted, comparing current grading schemes to the old guys may or may not be a fair comparison. Their greens were often smaller, there was less irrigation, etc. On the other hand, they built topsoil greens vs. USGA sand, which may have leveled the total drainage amounts out. Either way, did I mention drainage, drainage, drainage?