Those are essentially specialisation perks, thats why they increase the damage output. Almost all RPG games feature some way for a character to specialise in a given weapon with the reward higher damage output with that weapon either by direct increases or by new skills.
i disagree, they are only specialization perks if they were groups in a similar section, since they are given the same importance as all perks, you cant call them specialization, or you have to call all them specialization which neutralizes the point regardless.
and its a glaring flaw in many rpg's, its not fun to do more damage if it looks exactly the same, but given new abilities that alters how you do said skill, is fun

