I'd be willing to bet that Sakaguchi has read "The 5 dysfunctions of a team" [1]. One of my favorite books about how people jell together in groups.
Like him I was also in a military setting before I became a programmer. I haven't yet experienced the same level of engagement and team cohesion outside of the military but I believe that the answers are to be found in the kinds of insights that studies like this uncover.