Board Thread:Theories and Speculation/@comment-25093611-20160821131910/@comment-25122992-20160822101113

Well, as I already said, Oro/Sasuke and Tsunade/Sakura didn't got SM because of the rule of "eyes-body" power divided between Hagoromo's sons and their descendants. Sasuke's abilities are based on visual prowess, the "eyes" power, and were unlocked automatically, with no training involved, while those of Naruto (SM including) belong to the "body" branch and needed a lot of hard training to achieve, which corresponds with Indra/Asura natures (genius/hard-working looser).

Also, I know that Oro invented CS as a replacement for SM which he wasn't able to master, but there's a question - why Oro never wielded and used a CS himself? Once, I had an assumption, that since CS is essentially senjutsu, those compatible with it have a potential to learn an actual SM as well. Sasuke proved to be compatible as well, so Oro could've sought his body not only because of the Sharingan, but because with the right body he could've got a chance to eventually master snake SM at its fullest.

Anyway, it's still somewhat illogical that at least two of the Sannin animal kinds (toads/snakes) were said to practice and teach their own kind of SM, while the third kind (slugs) was never mentioned to have a one. I admit that Strenghth of a Hundred Seal is a powerful jutsu on its own and doesn't need to be augumented further by SM, yet if we learned at least something about Shikotsu Forest and SM of their, the "Sannin" sceme of SM kinds would become complete.