Thanks. I just trained the Mermaid Field 3 and it was decent experience with a full royal party. One map that someone pointed out to me if I wanted to solo in was Phantom Schoo 2F - Chilly Hallway. Just by myself I was getting .3 per Maiden Ghost compared to the .5 I get from a Water Weed Witch when I'm in a full royal party.
Just food for thought.