I don't see the reason of using Alternate animation tags for a Phoenix model, unless the custom attachment SFX requires you to do so, for which there is the field bellow the one in green on my screeny.
If you needed spell animations, you can type them out in strings ("Morph, Alternate" (as like you'd type out "Spell, Slam")).
To fix the base up, just remove the green field on your Phoenix Hero by deleting it's content.