Hardee only took the regiments which were under his immediate command at and around Pocahontas:

1st [15th] Arkansas Infantry
2nd Arkansas Infantry
5th Arkansas Infantry
6th Arkansas Infantry
7th Arkansas Infantry
8th Arkansas Infantry
6th Arkansas Battalion Cavalry
Clarkson's Arkansas Battery

Joining Hardee later were:
Roberts' Arkansas Battery, left behind awaiting a delivery of guns and ammunition.
9th Arkansas Battalion Infantry (formerly part of McCarver's 14th Arkansas Regiment).

There were several other Arkansas regiments, not under Hardee's immediate command, which were sent across the Mississippi River shortly thereafter to reinforce Polk, including the 9th, 10th, 11th, 12th, 13th, 15th (Gee/Johnson) Arkansas Infantry, 2nd Arkansas Battalion Cavalry. And then, of course, the flood gates opened when Van Dorn took just about everything that was left and crossed the Mississippi.