This thread was resurrected (for good reasons) and after I reread it all again it would seem that this conclusion still stands:
I think Steve Carrow is right on figuring that it behaves like the dialogue system and adjusts for the problems during game load.
But the Wiki is telling moders to put the idles at the bottom?
Unless I get feedback on this telling me not to do so I will be editing that out of the wiki.
See here:
http://cs.elderscrolls.com/constwiki/index.php/Idle_Animations
it is under the heading of compatibility.
If I understand this correctly putting the ildes at the bottom means that Pick Idle in your script will have to HOPE that all the other idles do not trigger as the manager searches the list all the way down to your idle.
Please tell me if I am incorrect on this, I am not an expert on the idles but most of the experts on moding oblivion are sometimes too busy to edit the wiki.
It looks to me however from the edit history that maybe "The Magician" did the entry and then "Qazaaq" did an edit? If so I would not presume to know more about the idles than they, but if they did not originally create that entry I am uncomfortable with leaving it As Is with out anymore discussion on this.