I've seen the AI play out several enchantments instead of playing Serra Enchantress first and then drawing cards for every enchantment it plays afterwards. The enchantments in question were both 3cc (Serra's Boon and Fortified Area) and even puting the Enchantress into the deck was meant to give value to casting those.

I think it's sort of safe to assume that if Verduran Enchantress or Serra Enchantress are in an AI deck at all, that having at least one on the board should take priority over pretty much anything else. There's no reason for them to be in a deck otherwise.