The 5th Arkansas Infantry was not part of Johnston's Vicksburg relief force which was engaged at Jackson. I don't know where that website got its information. The 5th Arkansas had not been in Mississippi since June 1862, when it was briefly in the Corinth area. During the period November 1862 to September 1863, the 5th Arkansas was in Buckner's/Cleburne's Division of Hardee's Corps, and was involved in the Tullahoma (Tennessee) campaign when the Jackson fight was going on. No stragglers from the 5th Arkansas are known to have been anywhere near Vicksburg, nor is there any indication that any of the regiment's wounded or sick soldiers were sent to hospitals there. The 5th Arkansas routinely sent its casualties to hospitals in Tennessee, Alabama and Georgia at various stages of the war.

The "Brownsville Rifles", Co. G, 5th Arkansas, was raised at Brownsville, Prairie County, Arkansas, and consisted almost entirely of Prairie County men. It received no conscripts from any other counties, though it did receive a few transfers from time to time during the war -- all of whom can be accounted for.

Okay, with that out of the way, I believe I have the answer to this mystery --

Three other Vicksburg parolees were identified as members of Co. G, 5th Arkansas Infantry, all paroled on July 8, 1863 -- four, if you count John Rose's amended record. While the company designation doesn't match, the names closely match men who were members of the 30th Arkansas Infantry who were captured at Madison, Arkansas, on March 7, 1863, and sent to St. Louis, then Vicksburg, for exchange, and apparently got stranded there during the seige. The kicker is that the 30th Arkansas was also called the 5th Trans-Mississippi Regiment, which the men themselves referred to as the 5th Arkansas.

Note that the 30th Arkansas was exclusively a Trans-Mississippi unit, and had no relation to the "real" 5th Arkansas or the 30th Arkansas that was later redesignated as the 25th Arkansas.

There was a man in the 30th Arkansas (aka 5th Trans-Mississippi/5th Arkansas) named John S. Rose who had enlisted as a conscript in Co. M at Wittsburg, Arkansas, on June 29, 1862. This company was disbanded on September 8, 1862, and most of the men were assigned to Co. B. Private Rose's rather confusing service record seems to indicate that he deserted variously in July 1862 and February 1863, yet was captured with part of the regiment at Madison, Arkansas, on March 7, 1863. He was described in U.S. prison records as age 30, eyes gray, hair light complexion fair, height 5'10". As I said, three other men from Co. B, 30th Arkansas, also ended up at Vicksburg, where for some reason they were listed as privates in Co. G.

At any rate, this John Rose doesn't match the ancestor that Larry is researching, either, but perhaps it helps solve another little mystery.