Battle script substitution?

[JonBrave]

OK, let me try another one. It's to do with what mages "can" or "can't" or "won't" do.

I'm think especially of holy spells, like bless, sermon or banish.

For bless/sermon, do I detect that mages recast it even if everyone who could be has already been blessed/sermoned? I think maybe they don't if Divine Blessing/Fanaticism has been cast, but otherwise they seem to? Or does that only apply to sermon, not bless?

For banish, I could be wrong (often am!), but sometimes I see banish cast when I don't see any undead at all.

For non-holy spells which require a specific "target", if target not available, does that count as a "substitute"? Say I have "Magic Duel" scripted and there are no Astral opponents --- I guess that means he substitutes... oh dear!