Hiya Mooch,
My first thought is you're asking a trick question, or which bunker style are you after? Alwoodley...or Meadow Club...or Cypress...or Oz (Royal Adelaide, Royal Melbourne et al) (as original)? My second thought is you're hiding the ball on us, and have some sort of point to make.
No matter, I'll take the bait. And so we go back, if not to the beginning, then to the beginning of his camo / engineering career. He learned a lot from the engineering end of things, specifically the Royal Engineers' construction methods of trenches.
Much of this learning amounted to the imitation of nature.
Sir! I refer you to "Golf Architecture," pp 48-50:
"Hummocks and hollows should be made of all sorts of different shapes and sizes, and should have a natural appearance, with plenty of slope at the bottom like large waves. Most of the hummocks and hollows should be made so smooth that the mowing machine can be used over them. The glorified mole-hills one sees on many courses should be avoided.
"Bunkers on an inland course should, as a rule, be made in the opposite way to what is customary. At the present time most bunkers have the hollows sanded and the banks turfed. It is suggested that you get a much more natural appearance if the hollows are partly turfed over and the hummocks sanded, as in the photographs in these pages. This has the following advantages: the appearance is much more like a seaside course; the sand being above the level of the ground, always remains dry. The contrast between white or yellow sand and the grass helps one to judge distances much more accurately, and enables the ball to be found more easily, and the great disadvantage and expense of scything the long grass on the hummocks to prevent lost balls is done away with.
"Ordinary bunkers are, as a rule, made in quite the wrong way. The face is usually too upright and the ball gets into an unplayable position under the face. The bottom of the bank of a bunker should have a considerable slope, so that a ball always rolls to the middle; the top of a bunker may, as it usually does in nature, be made to overhang a little so as to prevent a topped ball running through it.
"Experience gained in the imitation of natural slopes in bunker-making was ultimately responsible for saving tens of thousands of pounds in revetting material in the great war.
"Trenches with the side made like a bank of a stream with a considerable slope at the bottom remained standing without any revetting material."
Emphasis added.
In his lecture to the US Army on the construction of trenches, circa 1917, he goes into great detail on the proper construction of trenches. The accompanying illustrations bear striking resemblance to his bunker designs or at least writings on bunkers such as the excerpt above.
Yours in Mackenzietude,