How does fence placement work if multiple people are competing for a tile? Does it matter who places their fences inside or outside of the others? Like if 4 players have fences in between 2 tiles. Or is it that once the tile is owned everyone's fences are moved/removed as appropriate?
You are correct. If the tile is not controlled it doesn't matter where your fences are placed in regards to them being "inside" or "outside" anyone's fences. Once someone takes control of the tile just move everone's fences to the outside unless they are completely surrounded and can't possibly be outside. In which case they are removed from play and returned to the players supply.