Do you wear headgear with the combatives or combat focused uniforms?

The commander dictates the uniform. There is no such thing as a combative uniform, the uniform used for combatives is a modification of other uniforms. When I joined and it was still Combatives and not MACP, the uniform was brown t shirt, BDU top, ranger panties, and sneakers. Obviously that’s no type of uniform either, it’s a modification designated by the commander.

If you had worn your headgear someone else would have told you that you should be wearing patches and boots. One guy who was a prior drill told me that you couldn’t wear your hat without your gloves. Point is, people will always spit some BS reg they’re sure they heard. It’s incumbent on them to prove where it came from and not on you to disprove it. Hitchens Razor: what can be asserted without evidence can be rejected without evidence

First, you were in the right, in one sense, because your Commander gave no prescribed uniform immediately after PT, the uniform you were in was prescribed uniform for training. You were also in the “wrong”, in that as an experienced and disciplined Soldier, having pride in your appearance and ILO of proper procedure or guidelines, you do what is the hard right, (bring boots, headgear, and accoutrements and change into them prior to leaving training) over the easy “wrong”. It is an inconvenience but it’s part of being disciplined and initiative to make good and responsible right thing. But, if, you were on a plane and your Commander told you leap from the plane, wouldn’t you ask for a parachute, if you didn’t have one.

AR 670-1 para 2–8a
Senior commanders may prescribe the uniform for wear in formations. When not prescribed by the senior commander, unit commanders will prescribe the uniform for wear in formation.