... Why would they use a weapon when they'd have a creature who could breathe fire listening to them obediently much more easily?

[It's not that he can't see Astrid's point, but the fact is that normal weapons just seem to be too difficult to get and, as hard as it might have been to accept, Sasuke would sooner see the people here using Pokémon as their tools than trying to sneak around with contraban.]