I just found this snippet from The Naruto Saga: the Unofficial Guide interesting:
“Sasuke is naruto’s friend and rival. Actually, this name is very commonly given to Ninja in Japanese fiction, and many Japanese probably mentally connect the name Sasuke with Ninjutsu. The roots of this go back to a series of novels titled ‘Sarutobi Sasuke’ that were written in the Taisho era (1912-1926). Sasuke is a fictional Ninja, but in the novels he appears as one of the ten heroes of Sanada Yukimura, an actual warlord during the Warring States period. The novels were a huge hit, and the name Sasuke became associated with Ninja characters. This association was further cemented in the 60s when Sanpei Shirato created a manga about a young Ninja named Sasuke. This manga also enjoyed great popularity, and was turned into a television anime series. In modern times, the manga Sasuke probably had more to do with popularizing this name as a conventional Ninja name.
Going back to the novel, Sasuke’s family name Sarutobi has also become associated with Ninja. This connection can be seen in the character Sarutobi (the third Lord Hokage) and in Asuma Sarutobi’s name.”
Ref: p.42 Kazuhisa Fujie, Matthew Lane, & Walt Wyman (2008) The Naruto Saga: the Unofficial Guide. Mysteries and Secrets Revealed series 8. DH Publishing, Inc. Tokyo