Not sure if this is too old to be worth replying, but maybe someone will find it useful

I only have two druids, so my macro is somewhat simpler.

I have (from memory) on my main:
/cast [@mouseover,help,dead,combat][mod:alt,help,dead,combat] Rebirth; [@mouseover,help,dead][mod:alt,help,dead][] Revive

I tend to just use the mouseover res on my main though, so much that when I'm on my priest I press that keybinding to try and res people (which is instead bound to my wand).

Alt has:
/stopmacro [mod:alt]
/cast [@Kel-target,help,dead,combat] Rebirth; [@Kel-target,help,dead] Revive

I'd suggest trying something like the following for what you are trying to do:

Healer

/cast [@Vuhdo,dead,combat] Rebirth;[@Vuhdo,dead] Revive (so it will try to rebirth Vudho if your healer is in combat and if Vuhdo is dead, if you're not in combat it will try to Revive Vudho if that character is dead).

Then I'd put the following on a round robin for you other alts (so you don't get them all trying to res the same target at the same time). If you don't use an addon that allows for round robin casting then you could try /castsequence, but I'm not sure how that would work with different toons dying (using empty , , so they don't all try to cast Rebirth on the same keypress, if you're not sure what I mean either I can add an explanation, or look up a mage round robin frost nova macro, normally used the same principles). The conditions would remain the same.

/cast [@target=Vudho-target,dead,help,combat] Rebirth; [@druidyouwanttores,dead] Revive

For the Revive part you could either go for [@Vudho-target,dead] to manually pick a target, or set it up so that alt1 tries to res alt2, alt2 tries to res alt3 and so on. Might get a bit clunky if you have a lot dead though.