Can a BDE Commander designate an O3 to be HHC commander without an HHC commander position on the TDA?

Yes, if the BDE is delegating command authority to the 03 to serve as a commander it can be done. The commander can fill the position with whatever AOC he/she wants. The title of the original billet doesn't matter. That can be renamed too. So the ORB will reflect what is on the OER not the position being filled. Good luck telling an 06 he can’t fill his unit as he wants to.

Yes. This is actually how I got command. It was a task force that never had an HHC so things like logistics, maintenance, admin, etc were not getting done. So three commanders before me, the TF Commander established an HHC Commander and designated company positions out of the Soldiers he had (o room clerk, supply Sergeant, etc.) I always figured it would have been looked on in my career as a “lesser command” because of the odd way it was established, but I have a company command OER that covers 13 months and it is looked at like any other company command OER. Like the Colonel said before me, good luck telling a Brigade level commander how he should task organize his units.

I personally don't believe he has that authority unless the actual UMR Position is a designated as a Command position (i.e, HHC Commander). You can request a UMR/MTOE "Request for Change", but it to must be approved in my opinion. I've been out for a while, but as the Bridage Commander of three different units the MTOE/UMR dictates the Command Slots within a Brigade and those are filled by qualified individuals that DA Picks or they are selected by a process. The HHC Commander position can be requested and selected by the Brigade Commander or the STB Battalion Commander in a Sustainment Bridage, but the STB Battalion Commander and Brigade Commander positions are Board Selected. There may have been changes since I served, so anyone can correct me, if they feel I've got it wrong. I hope that answered your question CPT (Join to see)