Itachi in one night brought the Sharigan numbers to only 3 people Itachi, Sasuke and Obito/Kakashi sines they shared an eye each. Now chapter 10 Naruto Gaiden Naruto has increase the Sharigan population from Sasuke and Sarada to uncounted numbers by allowing Sharigan Children to join Konoha. Kami has a strange sense of Humor, don’t you think?