I made a macro for my shamans yesterday. It took a while to change names for every char.

#showtooltip Ancestral Spirit
/target toon 1
/cast Ancestral Spirit
/target toon 2
/cast Ancestral Spirit
/target toon 3
/cast Ancestral Spirit
/target toon 4
/cast Ancestral Spirit
/target toon 5
/cast Ancestral Spirit

It will ress the guy that died. Then for your second toon make this macro:

#showtooltip Ancestral Spirit
/target toon 4
/cast Ancestral Spirit
/target toon 1
/cast Ancestral Spirit
/target toon 3
/cast Ancestral Spirit
/target toon 5
/cast Ancestral Spirit
/target toon 2
/cast Ancestral Spirit

And just make the same macro for your other characters, so they start ressing an other character.
For example: if toon 1 and 3 dies, and you only have the first macro, your other shamans will start ressing both the same guy.
So with the target difference toon 2 starts with ressing toon 3.
Toon 4 will ressurect toon 1.

I hope this worked,
Negativ1337