"Roger, do you know which other units went into the 2nd Arkansas Consoldiate. Do you know which regiments were consolidated into the 3rd Arkansas Consoldiated?

Clues as to component units taken from CSR’s at the Footnote web site:

11/29/64 HQs 3rd consolidated regiment Arkansas inf, McNair’s brigade, Camp Lee-
Col H G P Williams-recommends Sgt Spinks Co D 15th Ark as Lt-Capt John Meak cdg regt.
Spinks’ unit now consolidated and he is in the 5th Company of the 3rd Arkansas consolidated.. He has been acting as an ensign since 7/22.
This regiment[15th Ark] is now consolidated with the 19th & 20th Ark as the 3rd Consol per Dept Orders.
It has been regularly mustered and the muster rolls sent to Richmond.

2/8/65-Scull-HQ-12th, 18th & 23d Ark regts & 1st & 12th Ark bns consolidated T R Reid Col cdg-Camp Magruder--of McNair’s bgde-Reid submits Scull of 18th Ark to be ensign-acting as such since 3/17/64

As shown in the field returns in my last post:
Colonel Reid [12th Arkansas] commanded the 2nd Arkansas Consolidated Infantry regiment.
Colonel Williams [Dockery's 19th Arkansas] commanded the 3rd Arkansas Consolidated Infantry regiment.