Well, the relevant passage in my post from The Young Lions is this:

"The OFFICERS IN COMMAND of the sand battery garrision hesitated, undoubtedly deterred by the prospect of actually firing upon the Stars and Sripes."

I don't know who those people might have been, but it would seem to be the only possibility that would allow for Branch to have been in charge.

I don't think The Young Lions is the authoritative text on this issue, but it was at hand. I have checked several other sources for Branch, however, and I don't find him -- except as the commander of the 1st SC Militia Rifles.