I think that the presence of magic REALLY skews things a lot. I suspect it's a lot more pervasive than we might think, which could explain why spears and bows are a match for firearms. While Garlean technology DOES give them an advantage, the advantage should be OVERWHELMING, but the game presents it as just an edge.

Because of magic, a lot of more primitive trappings hang around technological advances that SHOULD make them obsolete.