My answer would be both, depending.
I typically use a shoulder bag for rifle events and a belt bag for pistol events.
My horn is attached to the bag straps as a rule, the short starter goes into a loop on the bag and the powder measure slides into a pouch on the strap. The inline musket capper also goes into a pocket next to the measure.
For pistol events, I have the bag set up with an antler handled brass loading rod carried in a loop on the side of the pouch, and the powder measure is carried in an inside loop, along with the tubular flask. I use a Tedd Cash universal capper carried on my belt.
A place for everything, everything in its place, and nothing dangling around.
Works for me.
John