User blog comment:Ḡwẵine Ḹٍٍkƨ Ĺiĸe Ͼềлȑềd/Morgana = Coyote?/@comment-4650675-20121102090633/@comment-5674726-20121103114734

Morgana's arrogance always leads her to underestimate her opponents and allies: she wasn't banking on the depth of Arthur's love to take back Gwen and marry her (you know she was spitting nails on that one.) 

I'd say that's more a plot device than anything else, particularly in terms of Morgana's role in the kiss never being discovered so they can have the whole "love overcomes all" thing.

Had Morgana adopted a more practical approach, and had Lancelot slit Guinevere's throat instead of giving her the bracelet when he visited her in her house, there'd be no question of a dead Guinevere becoming Queen. She'd have been past saving, even by the Cup of Life, by the time her disappearance was noticed the next morning. Same goes for if she'd killed the unconscious Merlin - who has proved himself capable of being quite a thorn in her side, even if she doesn't know about his magic - instead of brainwashing him. There was no way that the writers were going to let that happen.

If Morgana ever learned that shooting is not too good for her enemies, she'd be considerably more successful but she's never going to be allowed a significant, lasting victory.