Well I name them "Sannin" because, well they kind of deserve it. Being the students of the previous Sannin, and continuing in their name. I doubt Hanzo could stand up to them.
Well because you have to think about it like how it is. Circumstances do not really apply to non-Hokage characters, seeing how not even Tsunade trained Sakura all the way (She learned her skills through Shizune via Databook). Boruto does not seem to like Hokage's at all, and I doubt Kishimoto crafted his character only for him to love Hokage's in the future. Understanding them? Yeah it might play a part in his development as a character, in which he sees things differently.
So taking that understanding while reading the chapter, and the spoofs. I can definitely see Sasuke taking him under his wing. Hell Kakashi was Naruto/Sasuke/Sakura's sensei too, but they all eventually found their true masters; Jiraiya, Orochimaru, and Tsunade.
