I researched each one of these men listed and can find nothing that will corroborate an official unit known as the 11th Arkansas Cavalry. Six of the men were official members of Poe's Bn Cav, ten were probably serving with the 11/17th Mtd Inf as they were either captured in Miss (capture papers show them claiming service in 11th Ark Cav while they were captured in 11/17th territory)or they were conscripts/volunteers from Miss where the 11/17th was operating. Some of these men were also listed onthe surrender rolls at Jackson, MS or Citronella Ala with the other men of the 11 and 17th Mtd Infantry.
Eleven men were captured during Oct 1864 when Union forces sent scouts out towards Princeton etc. One of these scouts was a multiple day affair and resulted in heavy skirmishing around Princeton and then the ambush set by Logan at Hurricane Creek...2 men captured at Benton onthe way down and 12 more from Logan's force. The Union officer reported these 12 men belonging to Logan's 11th Arkansas Mounted Infantry so they used their old name. There are also a hodgepodge of men from various units that either were captured and paroled at Port Hudson, or deserted their commands elsewhere and crossed the river some units represented were 18th Ark Inf, Hardy's Infantry, 2nd Ark Inf, Crawford's Cav.

So with that said I believe there was no official 11th Arkansas Cavalry. I believe that the only official unit was Poe's Cavalry BN and I believe many of them refered to themselves with the 11th Arkansas designation. Sometimes they claimed service with 11th Infantry, 11th Cav or 11th Mtd Inf. Here is the info regarding organizing of Poe's unit: "This, Poe's Bn, is a portion of the 11th Ark Vol Regt, Mounted Infantry, now east of the Mississippi River. These men were captured at Port Hudson and other places. Some deserted the regt until a good portion of said 11t Regt were scattered throughout the State of Arkansas. Volunteers have been collected and formed into a Batt of Confederate States Cavalry." One other thing to be aware of, in 1864 the 11th and 17th Ark rec'd a furlough for the whole unit. This was after Logan had went back to Ark. There was some mix up in Ark and they were told to report to Logan at end of furlough and Griffith played hell trying to get them to return to Miss and his command. Many simply joined their former comrades in Ark whether officially or not. It was what most wanted anyway, transfer to Trans Miss. I feel that Logan's "regiment" was in actuality Poe's BN with the attached men from other various units who seemed to have joined but after the time Poe's BN was officially reaised and mustered. I think that when Logan was given a brigade very soon upon his arrival in Ark, any men he had collected were placed in Poe's BN.

So hope this isn't too confusing, I think the CSR cards headed with "11th Ark Cav" were created by the folks in DC when they were going through the original docs to create CSR's on each soldier.