I only run 4 toons, but what i do is the following.

Add Strafe left on 1 follow toon to / which is the keybinding on the numpad
Add strafe right on 1 follow toon to / which is the keybinding on the numpad

In isboxer i just made a new key to send / to my toons which would make

....X
X X X

Just a heads up . If you use / in any of your slave keybinds make sure you unbind it from your other toons. Its default key is Walk/Run toggle.