Jim, I don't have the readily available details that you present, But I will comment to what I've observed from general discussion and studies.

It would seem that the early organization of unit in 1861 was volunteer. The early enlistments papers were treated something like a contract agreement and there wasn't any mandatory conscription until April 1862. While some regiments recruited expressly for Confederate service such as in the 1st Arkansas where there was little doubt they they would be traveling out of the State, others were made up of local militia companies that had volunteered to defend the State of Arkansas.

It seems to be theses regiments, which had volunteered for Arkansas service only in 1861 or were made up of local prewar militia companies, where you see the large numbers of "left in Arkansas" when they were called up to be transferred east of the Mississippi. It also seems that these men, who stayed in Arkansas, remained in service in local Militia companies or State Troops units until the Conscription Act effectively ended ablebodied men being in these units.

It seems that in late 1861 in certain units you could join the army and would still be able to choose if you wanted to be in "Confederate Service" or not. This is the reason I believe for the "left in Arkansas" notations.

Where we have records of pre War Militia Companies joining regiments that were later transferred east. Such as the Jefferson Guards or the Southern Guards and Major General James Yell of Pine Bluff. I have found less than 30% of those companies rosters transferred to Confederate service. Many of the Officers that did resigned shortly thereafter and a lot of the men came back to Arkansas after their 12 month enlistment was ended to join or be conscripted into other units.