Question for the group. The Cadian Battlegroup presents some questions for me. I was hoping the new FAQ would help, but it appears to have left this subject even more in the dark. I'll set it up as best I can:

The Astra Militarum codex treats Commissars different than Primaris Psykers, Ministorum Priests, or Enginseers. Commissars state in their rule entry "You may include one Commissar for every Company Command Squad and Platoon Command Squad in your Army. . ." The other 3 similar non-HQ units from the codex start with wording that is different from the Commissar, but identical to each other. "Each Astra Militarum detachment may include. . ."

Furthermore, the new FAQ's address the later 3, but do not address the Commissar. The question was "Can you add Ministorum Priests, Primaris Psykers, or Enginseers to Formations?" GW answers "No", but it doesn't address Commissars.

So, using the evidence I gather that you can include Commissars in the Cadian Battlegroup in accordance with the codex. GW did not address them in the FAQ, but did address the other units. Also, the wording states "Army" instead of "Detachment" in the codex, which further supports that they are essentially an option for PCS/CCS's. It also seems to match the fluff (although I'm no fluff expert).

The strongest argument against Commissars in a Cadian Battlegroup (outside the auxiliary formations) I've seen is that all options are included in the CCS/PCS sections. IE, a Chimera/Taurox is specifically listed in each unit as an option, instead of listing the units each transport is available to in the transport section. Therefor, Commissars aren't meant to apply to just any CCS/PCS.

Are there some rules references I'm not tracking, or is there a better argument to be made either way? I've got my paint scheme nailed down and am ready to start mass producing Guardsman and would like to be able to articulate any gray area well for my opponents so they don't feel cheated, and I don't feel like I'm in-necessarily handicapping myself.