Sorry Tom, I got my commanders mixed up. It was Frost. I know how much problems that it is to try to track little know units movement. Frost was kicked up to divisional command.
There is a gap in Major Schaumburgs report that I haven't quite gotten worked out. Since by both Pinell's account from Mitchell's 8th Missouri Infantry and the combine service records muster roles of both the 8th and John Clark's 9th Missouri Infantry record that the sick were left at Pine Bluff on July 27th, '63. So Schaumburg couldn't have been reporting on the conditions of these troops at Fort Pleasent in August '63. Maybe July of '63 in the short period of time between July 11th and the 27th. I say that because most of the men of John Clark's and Musser's Battalion had just returned after a month long campaign along the Mississippi River harrassing Union Shipping on the 11th. That probably accounted for the poor condition of the Missouri troops noted in Schaumburgs report.
Daniel Frost took command of the "defenses of the Lower Arkansas River" with the departure of MG John Walkers Division to Louisiana in late April '63. Col John Clark pretty much assumed command of Frost old brigade and Fort Pleasent at that time. But I don't think it was officially reconized.
I do not know right off hand what other units constituted the remainer of Frost "Divisional Command" on the Lower Arkansas River that Schaumburg is talking about in his report other than "Clarks" Brigade which included Hardy's Regiment while they were at Pine Bluff. Unless Schaumburg is including the cavalry at South Bend/Jordan's Plantation. Or was Schaumburg conferring "divisional Conmmand" upon Frost because of the scope of area of his command in Southeast Arkansas. Certainly I have not found indications that Frost commanded more than Clark's Missouri Brigade prior to August 1st '63, and that wasn't enough troops to warrent a "Divisional Command" in the conventional sence of the rank as I understand it. Frost should have been commanding at least two brigade in June and July of 1863 to have held that position.
Could the 2nd brigade of Frost "division" have been Tappen's Brigade returning from Louisiana? Is that how Hardy's Regiment became attached and later reassigned to Tappen Brigade? I don't know. For some reason the Arkansas Commanders seemed to reorganized the Brigade and Divisional structure ever 6 to 8 weeks.
Last but not least, both Mitchell's and Clarks Missouri regiments were made up with several Arkansas Companies in the organization. At some point in time either just before or just after the Battle of Little Rock these Arkansas companies were detached from the Missouri regiment and formed into other units. I believe that Bryan may have more information on that than I do.