Tillinghast wrote extensively about "showing sand" primarily to achieve better visibility, contrast, and aesthetics.
Have a look at any of the three Tillinghast books by Rick Wolffe, Stu Wolffe, and Bob Trebus for countless examples of Tillinghast's bunkering "styles", including some of Winged Foot.
It bothers me that there is an effort to pigeonhole classic architects into certain styles that seem to fit whatever someone prefers. For instance, in the case of Donald Ross, he designed ALL kinds of bunkers, as the pictures in "Golf Has Never Failed Me", or "Understanding Donald Ross" clearly illustrate.
These men were all site-specific, whether due to artistic creativity, differerent associates, or different crews.
In the case of Ross, not all or even most of his bunkers were the grass-faced ones that have become the steroptype today. He did flashed sand bunkers, artistic bunkers (i.e. Seminole), grass faced bunkers, pot bunkers, reverse bunkers, ragged bunkers, clean-edged bunkers, and a whole variety that I fear is often overlooked by restoration architects.
The place to start with any restoration, I believe, is with old photos, particularly ground-level, if a club is fortunate enough to have them in their possession.
Do we really believe that architects who provided the types of hole varieties and course varieties we've all experienced couldn't create anything but a single-dimensional bunker type??