Practically, how do you play? "Simultaneous" moves and arbitration via a Google Sheet or similar would be my starting place but maybe you've found another way.
Coincidentally, I was pondering Simultaneous Action Selection aka "we-go" chess recently, and thought of a way that could get around the randomization/priority problem.
Similar to you, both players choose moves. If players would go to the same square or if they would collide along a path, the pieces bounce back to where they started, and are frozen until another move is successfully executed. As an ad... (read more)
You could use the proceeds from this new land to put the remaining non-urban estuaries in California under permanent protection. Interesting proposition. The Dutch equivalent would be Almere, by the way.