4 shaman? Easy.

Put whatever spell you want on your main's bar.

Then put this macro on each of the followers:
[code:1]/assist <mainchar>
/cast <spellname>[/code:1]

For example, if you put "lightning bolt" as mainchar's button1, then the other chars would have this macro on their button1:
[code:1]/assist Mainchar
/cast Lightning Bolt[/code:1]

Furthermore, go to menu->keybindings and unbind all of your movement keys (i.e. wasd, q and e).

On one of your buttons, make a macro that just says /follow <mainchar> -- for example, put this on button "="
Whenever you want the shaman to follow you around, just press "=".

Finally, you'll notice that your following shaman will never break follow... So what happens if you want them to stand still? Go back to your menu->keybindings and make a "spread out" key. For example, set the button "g" to strafe left on one shaman, strafe right on another shaman, and move back on your last shaman. It can remain as nothing on your main character.

This makes the characters go from this:
[code:1]AB
CD[/code:1] (essentially all on top of each other)
to this:
[code:1]C A B

D[/code:1]


Ta-da. Instant multibox macros.