I’ll take a stab at this. Some context, I did not command an HHC. I commanded an AIT company that based on what I know had some HHC characteristics. I had an instructor population (~40-50 SSGs and SFCs) whom I had under my command, but were outside of my rating influence, effectively (I was their supplementary reviewer).

-Use your command influence. It can be difficult to things you need completed when you are not in a Soldier or groups rating chain. You have options to apply pressure (or reward) to accomplish the mission.

-Escalation of Force. This is the pressure mentioned above. While you may not rate or senior rate any of the staff, you have tools to get compliance with your requirements (IE: mandatory training, showing up to PT, completing NCOERs/OERs on time, MEDPROs, etc). Some of those tools (in my opinion, in order of consideration):

• Close working relationship with the S3/XO or CDR. If you have tried talking to the Soldier and their supervisor and the mission isn’t getting done, utilize your influence with these Leaders and they will apply pressure in their own way.
• Administrative Tools. You can try things like counseling, denial of pass, etc. You can also set (reasonable) suspenses for completion of items like mandatory training, and then hold feet to the fire (IE: You can’t go home until you complete this mandatory training I put out a month ago to be completed). Talk to the Field Grades before doing this, get their buy-in. They will likely support you 100% (and not go home until their mandatory training is complete).
• UCMJ. This is the most difficult one, especially when you’re having problems with senior NCOs and Officers. You need to ensure that the supervisor is counseling the Soldier who is not complying. If they won’t, have your 1SG do it to keep you as impartial as possible. Look into your CG’s policy on UCMJ authority withholding, it normally states a rank (E7/E8 is what I have seen) that the CG withholds authority for UCMJ purposes. Don’t think that because someone holds a certain rank, you can’t Article 15 them if it comes to that. You may not be able to take their rank, but you can still hold them accountable with the UCMJ (unless the CG has withheld authority for that rank). That said, think heavily before making it come to this.

-Reward. Do not shy away from using the positive tools commanders have. If you see a staff Soldier doing good things, talk to the Leader and recommend they find a time the Soldier can submit a pass for you to approve.

• Take a minute and think of how powerful a three/four day pass is. You can give “free” time off to those who meet the standards you set forth. If you look across other professions, this power is very limited.

-Do what you have to. Don’t be petty. Ensure you stay professional when executing negative actions. Don’t go around saying “Yeah, I got to FLAG *insert staff officer here* because they failed their APFT.” This doesn’t help anyone, especially when you have an entire company echelon depending on that staff member to get things done.

-Still do line company things. Make sure you sign property down, don’t hold it all on your hand receipt. Do maintenance, if the line companies need support, they will likely come to you for help.

The largest thing I struggled with was getting Soldiers completely outside my rating influence to comply. There is a lot to be said about the power of the rater/senior rater to enforce compliance with a task.