Your comment relies on a misunderstanding of what Aristotle - or his proxie here - means by the term "art". In modern usage, something that has no art to it is base, simple, and requires no effort to achieve. However, art meant something more nuanced to Aristotle (that nuance is why people still make a living arguing over the implications of what he said). For Aristotle, an art was something that pointed to the Good. Politics was the art of governing men, Ethics was the art of ruling oneself. These things involved skill - the skill you allude to the troll possessing, the power to weave webs of words and manipulate people - but also involved something more - an understanding that the purpose of the art was to further a good in some way. When "Aristotle" says there's not art in the troll's activities, he means they do not point to the good, and they will in fact do harm.

PS apologies if this isn't well reasoned, I just got off a plane and am a bit jet lagged.