These four Warrens are found in the Texas Cavalry Brigade. Both the Third and Sixth were from the North Central area of Texas. Company H was mostly from Bell County and Belton, Texas. Many were in Captain Whites Ranger Company before muster. Company E came from Shelby County TX and Company K from Smith County.

WARREN, D. S., Pvt., Co. E, 3rd TX CAV
WARREN, James F., Pvt., Co. K, 3rd TX CAV
WARREN, H. J., Co. "H”, 6th TX CAV
WARREN, Peter R., Co. "H”, 6th TX CAV

From tthe Soldier-Sailor listings from the National Park Service I found:
Warren, James C 3rd Inf Regt, Texas State Troops 6 mo 63/64
Warren, James C Cambers Battalion, TX Reserve Corps INF
Warren, James F 37th Texas Cavalry Regiment (Terrell's)
Warren, James F Yarborough's Company TX Inf Smith County
Warren, James L 35th TX Cavalry Regt (Likens)
At http://www.itd.nps.gov/cwss/soldiers.cfm I found 50 Warrens. Put in Warren, no first name, Confederate and Texas. There were no Union enlistees from Texas. Hope this helps.
Captain White's Company probably passed through Fannin County. You can see all the Entries from Smith County which is more east of Dallas where several of these regiments mustered.