Don't proceed like this, start by the control point first, in general the control point has to have a story, and as you are starting, you should make it simple, on a bridge, in a barn, on a cliff ...
Then when your control point is ready, turn around it and create the battle zone, after that add the pathS to access it, and ends with the spawns.
Don't stick with the units, each maps have their own, you just have to stick to these two size, 192 and 256 units for the heights.
Don't forget to play with the heights, it's very important to avoid the sightlines, and create an interesting gameplay.