It is impossible for Kishi to rank powers properly with this many abilities and characters. Going by abilities, Shino is better than Shikamaru, as well as a lot of other ninjas. But I don't think Kishi meant for that to happen, since he clearly has Shikamaru ranked higher based on his story and what has actually occurred in the manga. Shikamaru has been involved in big time fights and won thus far himself or with his ino-shika-cho team against Hidan, Kinkaku using 9 tails chakra, and Asuma. He even got to confront Tobi and put him in Kage mane no jutsu. Meanwhile Shino has been fighting White Zetsus the entire war. Going back further, Shikamaru was the leader of the Leaf 5 at the last arc of Part One, meanwhile Shino was left out of that arc completely. It is obvious that if Shino and Shikamaru were to fight in an episode of Kishi's naruto, Shikamaru would win. Even though if you really thought about their abilities and how it would play out in a fight, it would happen exactly like you said and Shino would win.