We have:
Hang em’ high
Headlong
Timberland
Battle Creek
Prisoner
Damnation
We should also have (Pre made maps so entirely possible):
Hemmorhage (Possibly build the tunnel off and call it blood gulch, one of two forge world maps to keep variety)
Reflection (Renamed Ivory Tower)
A more accurate version of Sidewinder (Second forge world map, keeps the CE theme)
Asylum (Made like sanctuary, just another FW map, renamed Sanctuary)
Pinnacle (Made like ascension, just another FW map, renamed ascension)
Ideas requiring other DLC:
Sidewinder, if impossible in FW
Death Island
Other ideas (Have at most 4 FW maps, try to keep it CE themed, but H2 is ok as well.)