Can a SPC (non team leader) sign as a supervisor in the signature block on a DA31?

CPT Lawrence Cable thanks sir! I was told though when I was inproccesing fort bliss by reception if a da31 didn't have a 0-5 or above sign for "non chargeable leave", it wasn't valid.

SSG (Join to see) - For the supervisor they wanted a O5 or above? Or the approval authority?

SFC Kelly Fuerhoff approval authority (last signature)

SSG (Join to see) - That is generally true. The places I have served, the approval authority was the Battalion Commander or above, usually Brigade or higher. Battalions are commanded by O-5's in the Infantry and Engineers. The supervisor's signature isn't approval.

Air Force if pretty much the same, an assigned position comes with command backed authority. As an example, back in the day I was assigned as Aircraft Commander for a movement of the Battalion Advance element first to Elmendorf, then on to Adak. I was a pretty new 2LT and everyone on the Flight Crew outranked me except the Crew Chief. The pilot made it very clear that he flew the plane, anything outside of that was my responsibility.
I had about half the Battalion staff on my aircraft, all of whom outranked me, but technically they were under my command until we off loaded in Adak. I didn't push that theory, but they all followed those rules.