Years ago, on the old jsettlers site, two popular game variants were reverse robber and reverse robber on 7.
Reverse robber means that the robber must be placed on an unoccupied hex if possible. If that isn’t possible, it must be placed on a hex that is wholly occupied by the rolling player. Finally, if that isn’t possible, it is placed on a hex shared by the rolling player and a resource is stolen from one of other players sharing that hex.
Reverse robber on 7 is a variant where knight cards work normally, and the reverse robber rule only applies when 7 is rolled.
My family and friends have instituted this rule when playing at home. It takes away a lot of time-consuming decisions during the early game and eliminates a lot of unnecessary bickering.