The FTL is based off of three mapped keys.
-- FTL Assist Me
-- FTL Target Me
-- FTL Follow Me

Anything using FTL conditions can be accomplished through calling one of these mapped keys.



If you were to remove auto follow (or strobe follow) on a character switch, this should be relatively easy.
Melee toons (along with your tank) should interact with target, which breaks follow.
Similarly, casters and healers will have broken follow a short distance away from the melee.

You'd need a mapped key for sticky targeting.
I believe Zanthor had one, which was posted a few months back.
You could try searching for posts by him, in reverse chronological order (newest first).

With a sticky targeting system, you'd need to push assist for the slaves to change targets.

You could probably just have a new mapped key made.
Which only sends the command to the current window.
The command could be a hotkey which all toons have a ranged attack on.
So for example, your hotkey might be "Alt + A" for an add.
Which sends "9" to the current window.
With every toon having a ranged attack on "9".
The mapped key does not have any assist component in it, and is broadcast only to the current window.
Which means, it does not change the targeting of the slaves.
And is not broadcast to them either.