Maybe we can break down into two man teams in matches. We can give them a universal name so once you're in that team you know what you are supposed to be doing.
For example:
Alpha Team
Bravo Team
Charlie Team
Alpha could always work the left side of a map.
Bravo could always work the middle.
Charlie could always work the right side.
So, for example on Mill. We would know Alpha always goes The Stone Bridge, Brave goes center bridge and Charlie goes to the Mill bridge.
We would have to figure out the specifics of each map and it doesn't have to be as cut and dry as left,right and center but you get the idea.
Just a suggestion