Aha, I'd originally confused your D with the DISC Directness.

Paul's subaltern comment reminded me strongly of "Life of Brian": https://www.youtube.com/watch?v=WboggjN_G-4&t=92s

Re: Rao, I found that I had to deliberately read https://en.wikipedia.org/wiki/The_Story_of_Civilization in small chunks with large breaks, because otherwise it all blurs together in terms of being a bunch of h saps being awful to each other. More specifically to his introduction, one can see big differences in the "tournament" between say 1250 and 1500: over that period they go from being a sort of open wargame with a racing-for-pinkslips feel played over the several km of hill and dale between villages, to a sport played in an enclosed pitch in front of an audience, limited to vetted entrants with the appropriate gear.