I believe there are two answers. My first answer is Acupuncturists are trained specifically in proper needle manipulation. Especially for the different between treating fibrous bands of muscle vs. local ischemia to benefit patients. What’s great is Acupuncturists can work together with PTs as an integrated form of treatment. 

My second answer is if you give PTs the ability to do acupuncture a.k.a. Dry needling... then add exercise therapy and manual therapy to Acupuncturists scope of practice. Also add a 200 hour course to allow adjustments for Acupuncturists.