Oh, I do think I understand his intent in his metaphor of the "tripod". And I will say that in one of the earlier chapters, where he is explaining Darwin's arguments for his theory, and putting it into the context of the science and natural theology of his time (especially in regards to Paley and to Lamarck), I think the metaphor works really well as an organizing principle.
However, I think that the "tripod" really served no purpose in the organization of the subsequent scientific challenges to Darwinism, nor to his description of contemporary attempts to extend the Modern Synthesis. Maybe Gould used to organize his own thinking, maybe it's more explicit in Kellog's work, but I really didn't see it in Gould's book.
I also didn't really see Gould mention creationism beyond a couple of very brief mentions. The book, after all, is about contemporary,
scientific attempts to extend the Modern Synthesis, not an encyclopedic description of all "challenges" to Darwinian, however on the fringes of common sense they may be.
As far as Gould's "legacy or notoriety", I do think that Gould intended this book to be seen later as a prescient description of where science would be going in the 21st century. I think that Gould was aware that some of the ideas presented would not pan out, but I'm sure he was confident that much of what was outlined would bear some kind of fruit, even it the results end up not being exactly where Gould thought they would be.
Actually, if their god makes better pancakes, I'm totally switching sides. --
Charley the Australopithecine