My understanding was you were trying to run two different groups. I see you are trying to run one group with multiple toons killing in the same group at different locations. You could try setting them to puller in kissassist, even on chainpull, but you still end up with the same amount of toons killing the same amount of mobs. Not sure if you can designate more than one puller in a group either.
Most of the scripts run off of the xtarget aggro and will attempt to assist any toons that have aggro.
The closest thing I could think of is running pocketfarm on all your toons and let them go at it.
As you run out of mobs they will all eventually end up going after the next spawn, but unless you are just running some type of custom script that ignores xtargets and just grabs and kills the next closest mob regardless there isn't much else for a group.