Been thinking over the issues involved with doing anything even remotely akin to Control Points in City of Titans ... because, golly gee whiz, they were just so much fun in Tabula Rasa ... and have been coming up with some really strange answers.
The basic idea still remains one of Capture The Flag, and would still be a World PvE sort of thing, instead of being a direct PvP oriented option (although creating an Arena map based on Control Points ought to be quite possible). However, in Tabula Rasa, you could get away with making Control Points into "forts" with walls and "doors" you had to batter your way through in order to enter the compound and take the Obelisk to switch "ownership" of the Control Point from the Bane to the Allied Free Sentients (the AFS). That entire premise of structure ... that you can have "walls" that PCs can't get over easily, thereby funneling them through the front door (which required a lot of DPS to open) so as to give you a "castle" kind of fortification that changes sides ... only "works" if you're dealing with a ground bound environment where PCs can't Jump or Fly or Teleport over those (speed bump) walls.
So in a Superhero game, particularly one which features a lot of vertical movement options, you can't build what amounts to 2D fortifications and require the PCs to break into them in a conventional fashion. Or at least, you can't do that without building a Roof over the location of the Flag to be captured, which then brings all "Indoor" considerations to what is supposed to be an "Outdoor" activity. So when Vertical Movement is the "rule" rather than the extraordinary, the fact that you can build (vertical) Walls isn't all that good of a protection/defense to fortify a position. It just won't work when PCs (or even NPCs, in the case of Prisoners leaping the fences around The Zig in Brickstown as though they were trifles) have enough vertical movement to render the Walls useful only against Superspeed.
So what to do if you can't have a walled compound to assault and defend?
Simple ... add more Flags to the area and require them to all be in a state of Capture simultaneously in order to "flip" the ownership of the Control Point.
How MANY Flags to assign to a particular Control Point then becomes something of an interesting question. I'm thinking that as few as 3 in a lowbie zone would be appropriate, and placing them close enough together that potentially a determined soloist of appropriate Level could solo capture a Control Point with 3 Obelisks ... but it would be "tricky" to do and prone to failure (mainly due to NPC Foes spawning in fast enough after being defeated to make this option difficult but not impossible). At higher Levels though, the number of Obelisks to capture simultaneously could be increased, going perhaps as high as 8 for a single Control Point in a high level zone. The basic notion however is to encourage TEAMWORK for both the Assault and the Defense states for these things.
Verbogeny is one of many pleasurettes afforded a creatific thinkerizer.