Tbh I don’t see it, bone release is cool cause it makes Kimimaro deadly and unpredictable and suits his taijutsu style.
Hidan is a wild monkey chasing after people with slow and easily choreographed attacks because he doesn’t need to worry about taking damage
I think you’d lose a bit of the appeal of Kimimaro’s fast and elegant fighting style and Hidan’s reckless fighting style if you merged them.