Sure we can distinguish the jack of all trades nature of Sea guard by price, but it feels more intuitive for them to be distinguished by gear aswell. They shouldn’t be as good as specialist citizen archers (they aren’t having bows not longbows) but they shouldn’t be as good spearmen as dedicated citizen spears either - which they are . Fluff wise - Given all the extra gear)

Why not allow our spearmen to have heavy armour, to give them a close combat advantage relative to Sea guard?

Yeah, that was my thought, a bit more anvil like, but ok, I take the point from @Giladis that citizen spears get an innate FIER on top of their spears’ FIER - which I guess does imply extra gear that would be difficult for sea guard to handle amongst all their missile stuff too - namely longer spears. So to enable them to fulfil two roles they have smaller and handier, and therefore shorter ranged, spears and bows