[Twan]

I'd like to see retreat order as well as all irrelevant scripted spells (large AE, battlefield enchants etc...) ignored in assassinations attempts.

Actually even communion slave is cast during an assassination, where there is only one mage on the field (and as well an air mage will cast storm or arrow fend against an earth elemental if scripted to do so). It's probably the most ridiculous aspect of the game, and I see no nation relying so much on assassinations that the current system may have a balance justification.

I'm having trouble imagining using "retreat" in scripted orders often enough for this situation to be a significant problem.

I agree retreat is not the worse problem (except... when it happens). I find the lone mage casting "communion master, marble warriors, (then nothing because he is at 100+ fatigue)" far more annoying.