I might as well jump in here. My forthcoming book on Confederate army colonels includes an analysis of the colonels of each state and their prewar military experience. My conclusion is that the colonels from VA had the most prewar experience, the colonels from AR the least. Not surprisingly, the Confederate army in VA performed best, the Confederate army in AR performed worst. I've mentioned this in talks in Houston and elsewhere.
There simply wasn't a large pool of West Pointers who came from AR. In fact, AR only had about 4 prewar USMA grads, and no VMI equivalent (and yes, I know about the military institute at Tulip).
The post-Van Dorn TMD army consisted of high-number second-tier regiments (those raised after the conscription act) with second-tier officers and with mostly left-over general officers. Plus their equipment consisted, particularly in the early stages, of the stuff Van Dorn had left behind--the artillery especially. As late as 1864 the governor of Texas was complaining he couldn't arm his "state" troops.
There were several competent generals in the TMD (Taylor and J. G. Walker come readily to mind) but on the whole they could only work with the material they had.