As Sakura said, Shintenshin is not easy to use, It's slow, risky, and predictable.
Besides, Ino is not a VS type Kunoichi, she is a Support type, a very good one actually. She is a great sensor, great telepath, and a regular medic, but she has very few feats in direct combat.
While Hinata is a Melee type, so she is way more trained than Ino in fighting by herself.
Hinata wins low diff.