To make fog semi-work, all opponents must not be able to see each other’s territories. A “spectator” would have to do the moves and update relevant players of the new situation without letting the other player know.
For attack analysis (with 0% luck modifier) you could use https://danwlgames2.000webhostapp.com/WL_WZ/WL_calculate_attack/WL_calculate_attack.html
. Had to rename the website as the provider decided to auto-delete my account and website associations due to being “inactive”.