Hello, so this is my first forum post and regards parking in planar tomb 3

So i do know the concept of parking which is to group together all the enemies in an area and re-enter the map or die, so they are rooted to one spot. However i have never had to use it till pt3 and i have no idea how to go about it.

The probelm i have is where do i take them?, Since pt3 consists of just circular rooms which arent too big(keeping in mind i have never crossed more than 1 room in my earlier try)
Since almost all parties formed by me ask me to park(being a war) , this is proving a great hindrance and i'd be extremely thankful if someone could help me out with this