Why can't commanders follow scripted orders?!

[moderation]

Hmm, your commander might be casting Astral Shield because he isn't allowed to spend gems on his scripted spell. Sometimes commanders aren't allowed to use gems if the game considers the opposing force too weak. Usually this is the case if you're fighting a few PD. I think it's revealed in debug as mayusegems:0.

And I remember reading that mages will refuse to cast certain spells if you script it in slot #1 for some reason. I'm not sure if that has been fixed though.