Cassie, with her STG powers, was more than willing and was at least partially informed as of MM4. And being an Animorph, she was directly involved with the cosmic game as it played out on Earth. I've been rereading, and the amount of times she says she has no idea why she does things just lends more credence to my headcanon. Cassie is the Anti-Drode for Earth, and that is my firm stance.
If we're going with the LotR comparison, then if Crayak=Sauron, then Ellimist=Gandalf. One uses vast armies under his direct control and has a creepy person to act as an intimidating mouthpiece (Drode's basically Saruman, Wormtongue, and MoS combined), while the other gathers allies and friends to fight under his gentle guidance. One creates expendable grunts by the truckcartload, while the other creates a select company of heroes with a handpicked mix of personal strengths/circumstances to form a strategically sneakier resistance movement with a more personal touch.
KAA was a big fan of LotR, it's interesting how many parallels there are if you look for them. I remember spending a while picking apart the ending to see how much it tied in (quite a lot, really).