Realistically, it will all come down to financing a permanently standing state army and the harm it will do by having so many young men being withheld from the economy.
However, it appears to me most likely that there will be a small standing army which in time of war would find its ranks swelled by state militias. The ration of CS Army to CS Volunteers officers and men would probably be pretty low. There would probably be very slow mobilization plans.
What immediately comes to mind is the British Army in the Great War, and how the British Army officers regarded and treated the colonial troops. The professional officer corps will probably be were true Confederate nationalism and a want for a greater centralized government would originate from. Thoughts of the Austro-Hungarian Imperial and Royal Army also come to mind.