I'm working on a map and I've come to a wall. I'm attempting to add the bases before I continue with the rest of the map. Problem is I'm not sure what to do next. As you can see, from the below image, I've placed a L structure at the bottom and a U structure at the top. The original plan was to mirror these structures onto the other side and flip them so the L is at the top and the U at the bottom.

I had also planned to place red & blue bases at the L structures. But if I do this, it'd place one team closer, then the other, to the top of the middle structure. This would greatly unbalance the map.

Should I continue with the side structures or scrap them?

Also, dies anyone know how to stop the terrain planes from moving out of sync? I've tried locking them, unlocking them, magnets, and procession placing them. But they always shift.

Video: http://xboxclips.com/SEspider/bdcca01c-6d2b-4d8c-a5b4-8da37faaeb9c