how I handled hex, I usually use focus targeting so I used something like
/cast [target=focus-target] lightning bolt

this allows me to have each character target his own target.
so I have my main place raid targets on all of the targets for hexing or sheeping
I have a button that allows me to set the target on each alt such as
/assist focus
so I have my main target something then have one of my shaman do /assist focus ( you can do this with a round robin key or a special key for each alt )
the xperl display shows what the alt is targeting and the little raid target displays so that I know each shaman is on a different raid target.

and on the hex button I didn't even bother to make a macro, i just put hex in there ( /cast hex )
pull to the group and press my hex button when they get close.