The mayor is not stupid, but his weak will gives Lann's [Yakxi Rune] a chance to exploit.
He cares too much for his gold, going so far as to count it twice in the treasury whenever he's free.
This obsession was keenly noticed by Lann and then amplified with the [Yakxi Rune].
The more he cares about his gold, the more he takes seriously and fears the news of the Beastmen coming to plunder. This fear overshadows his reason.
Anyway, even if the Beastmen don't come, it just means his guards are busy for nothing.
He doesn't care about people, not even those under him; he only cares about gold.
Alfred isn't stupid either, but he knows his power comes from the mayor.
Therefore, he would never go against the mayor; whatever the mayor asks of him, he'd do it unquestioningly, no matter how absurd.
Lann didn't use the [Yakxi Rune] to twist the mayor's will, although his will is very weak, the [Yakxi Rune] itself isn't strong either.
