Well, this recommendation is not FTL... as I was never able to get it working, prior to moving to IS Boxer.

If you were to make five macros.
/focus [target=ToonA]
/focus [target=ToonB]
/focus [target=ToonC]
/focus [target=ToonD]
/focus [target=ToonE]

Have all five macros on all five toons.
Have all the Toon A macros on the same keybind... etc.
So when you push Keybind 1, everyone including Toon A will focus Toon A.

You can then use:
/follow [target=focus]

And:
/cast [@focustarget] Frostbolt

And:
/castsequence [@focustarget] Frostbolt, Frostbolt
/cast [@focustarget] Frostfire Bolt

And:
/cast [@focustargettarget] Healing Touch

Etc...

It is not FTL, but you can switch to any window...
And set your Warcraft keybind for that character to be focused by everyone... to be the same as your software keybind, to switch to that window.
Any toon will be able to lead, and the others will assist it correctly.




I'm not sure how good the mouse broadcasting is, for Octopus.

If you're comfortable with your own scripts...
Take a hard look at Hot Key Net, which is free.

Also take a hard look at IS Boxer.
That's 36/year, but most likely the top boxing software option available anywhere.
Lots of things you can do with it...
Set up a 'Send Next Click' action, so you press the hotkey for Blizzard, and every mage has a targeting circle (which moves in real time, as you move the targeting circle on your main's window) and which turns the mouse broadcasting off, after you click for the Blizzard.
Not to mention, instant swapping between windows.
Automatic FTL.. meaning, put your spells on "1" in wow, press 1 from any window, and without any macros at all... every toon will do whatever is on "1", at the target of the current window.