Never change the winning team
So, there it is, your perfect banner. Finally approved by Niantic and fully online. Anxiously you wait for the first likes or dis-likes as agents follow the path of portals you laid out, in order to get the picture you so carefully chosen.
But, then one day you notice that you don't have enough missions in order to create new ones anymore.
Mission Authoring Tool 101:
Never ever re-use an existing missions in another banner !!
, but always unpublish a mission before you change it's picture. If you don't, you will alter the banner picture on everyone's scanner and your preciously selected creation will be ruined.