@DaLilFishie Not that I've ever seen at least. Sergeant Major refers to A.saxatilis alone, the rest of Abudefduf are just sergeants. Not surprised if it is used for most of the genus occasionally since many are pretty similar, but all the literature I've read restricts it to the aforementioned species.
@DaLilFishie Fair enough of a statement; Sergeant Major is the only Abudefduf I've ever seen offered in the NA trade and is most likely, though I don't doubt others crop up occasionally. The fish in question seems to match A. saxatilis closest in appearance to me, though I agree it's a bit difficult to say here.