Sasori is too powerful for Shinoi to take by himself. I know he has multiple insects at his disposal but the fact is Sasori's multiple puppets and his attacks are too much for Shino to handle alone. Pair with Chiyo instead of Sakura they could've taken Sasori down much sooner maybe, or even pair him with another skilled Aburame like his father maybe.
Shino is not underrated his position is just not emphisized because he's not a major protagonist or antagonist. I believe Shino is jounin level and should've been promoted to such level along with Neji over the time skip (although I don't see Shino beating Neji). Anyway back on topic, Shino is strong but he needs help when dealing with a Sasori, even give him Kankuro, at the time when he was beaten rather easily by Sasori at the time. Kankuro being a puppet user could cover and Shino could stratigize.