The true rule according to the 40k rules of that time was strictly the problem of the GD when it came to animosity. The GD's would fight each other basically to the death while the other minions fought on. The GD fighting basically gave their opponent victory points.
This disadvantage could cause the minions too make a morale test before they can do anything else, including orders.
>From: "ugoslave"
>Reply-To: netepic_at_yahoogroups.com
>To: netepic_at_yahoogroups.com
>Subject: Re: [NetEpic ML] [5.0]Chaos army list
>Date: Sat, 23 Nov 2002 02:42:02 -0000
>
> > >>>It seems we want animosity; problem is what mechanic to use.
>Zerloon,
> > gave me an idea which is a twist on his. The animosity stems from
>one
> > greater demon to another so as Zerloon mentions lets concentrate the
> > rule mechanic on that, after all the followers are just that-
>following!
> > They don't have that real reason to hate beyond their greater demon
>says
> > so!
> >
> > -->This works for me. The tests for animosity revolve around the
>GD's.
> > That way, if a test fails, that GD and his minions charge
>their "enemy,"
> > with out effecting the remaining army bits, and it's all in one
>roll.
> >
> > I thought it was simple to, hopefully others will agree too.
> >
> > Peter
>
>I agree with the animosity test only for GD, and if a GD fails all
>minions charge...
>but all minion of the same god ? or also chaos undivided minions ?
>
>and when they charge their "enemy", the "enemy" is the GD nearest or
>one target for every minions?
>