Of course, you are undoubtedly correct, and this north Mississippi boy is not going to challenge your knowledge of the "goings on" in the Pine Bluff area.
Based on the information about Platosz cdg the battalion, and the reference to Capt F. P. Hall subsequently cmdg said battalion, however briefly, I could not see how Captain McSwine could have had time to also have battalion command. So, I was looking for alternative reasons for Hindman's telegram to McSwine.
I wanted to point out that Major Platosz commanded the defacto battalion that you mentioned. And, to speculate about the number of companies involved considering Bragg's company most likely being attached to Pleasants' regiment vs Morgan's [Platosz's] battalion.
Finally, the identity of Captain Neale and Captain F. P. Hall may or may not shed additional light on the defacto battalion that eventually became Morgan's battalion.
Arkansas puzzles can be frustrating, but at least I think we are close on this one!