There's also a Legion Take Over ending for Primm. First, you have to make Primm join the NCR. Secondly, you have to leave Caesar alive. If Lanius takes over, Primm gets burnt to the ground. If you annex Primm to the NCR and leave Caesar alive while beating the game as the Legion, you get an ending slide that basically states:
"Despite NCR's pledge to support Primm, they abandon the town after their loss to Caesar. Though Caesar keeps Primm open for business, its citizens live under the constant watch of Legion soldiers."
It's actually one of the few Legion ending slides where they don't destroy anything belonging to the NCR.