Team Select Select NPC

[Rock and Paper]

I made an Hourly event custom BG that automatically starts even with 1 player on the map. There is a giant emperium on the middle with MVP's Guarding it, the 1st team to break wins.

So I Need Help on a warper NPC. Upon clicking on the NPC it will directly warp you to battle ground map. It will randomly choose between 2 teams.

Im having problem on the placement of team of players.  Can any one help me on this?