When the referee saves a game, there should be four files saved at the same time. One game file for the referee, and one each for Red and Blue players. The last file is a player settings file that is for the referee (actually all players have their own that is specific to whatever the player has set in the way of graphics and display).
I wonder if the referee is sending the players his game file and not the Red or Blue files. Setting perception would only affect the Red and Blue files, not the referee file.
Look at the file you have. You can open it with a text editor. If it says something like File:"Referee" then you have the wrong file.
The next version of SimPlot will allow players to set movement waypoints that can be exported as a JSON file. The referee can then import those files and the unit movements will be automatically set.
Kevin