Ooooh! But they do.
I had a bunh of them stashed away and when I wanted to use them for a display, I couldn't!
The joints leg-torso & torso-head had gotten 'soft' and they would either fall over or roll their heads back when displayed.
So my suggestion is (which is what I do) keep the lot of them apart and then build them when you need them for a MOC or display and then take them apart again.