in my chain of command, in the air force, we have squads, and a squad leader (who is typically an NCO, non commissioned officer). If I was told to do something from another squad leader, I would say, “yes sir” and say something like, “Sgt so an so is having me do this at the moment, as soon as I’m done, I’ll get right to it”. An officer position, like LT and up, generally hand down the work to the NCO’s and the NCO’s will tell me what to do (I’m a senior airman). However, if my commander came to me and told me to do something, there is no chance I would ignore it. I would say “yes sir” and would get right to it….if it contradicted what my squad leader told me, I would let my commander know at that moment “sgt so an so told me to do this, should I drop that and do this now, or just make sure it gets done today?” I’d just be sure to give my customs and courtesies to any person in a higher rank than myself too.