hello,
first you have to design your average site configuration (3×4 ?)
For a 3×4 configuration, it will require 12 frequencies, which are NOT adjacent. with your current frequency band (24 channels), you can barely get one “clean” site… but the next site will use all adjacent channels.
well, in this case you’ll need to use avery agressive frequency re-use planning and a perfect network design… and therefore you need an expert radio engineer to plan it and follow-up.