I suspect Hindman initially used the term Trans-Miss Rifle Regiments for a couple of reasons.

One was his conflict with Governor Rector and Rector's plan to create more regiments of State Troops.

Two was his rather dubious use of the Conscription Law to create new regiments, rather than use the manpower raised to re-enforce the existing regiments as was intended.

Third, his practice of appointing the officers of the new regiments, rather than following the traditional election processes.