Originally? How to do things wrong.
Many of the sample archetypes, as originally written, simply aren't very good at what they do. There's a sample character archive we put together that made the archetypes much better. For example, a disgusting number of the sample characters have "Uncouth", when multiple Incompetences in social skills would achieve the same thing for less cost and more BP gain.
However, in this case, you are right. I don't recall seeing an errata fixing the "Light pistol" specialization, so it stands that you can have specs outside of the listed ones.
Many of the sample archetypes, as originally written, simply aren't very good at what they do. There's a sample character archive we put together that made the archetypes much better. For example, a disgusting number of the sample characters have "Uncouth", when multiple Incompetences in social skills would achieve the same thing for less cost and more BP gain.
However, in this case, you are right. I don't recall seeing an errata fixing the "Light pistol" specialization, so it stands that you can have specs outside of the listed ones.
It's true that many of the sample characters are built oddly, and aren't as effective as they could otherwise be, but I don't know of any that actually break the rules (post-errata). In response to a previous post referring to the Troll Bounty Hunter, Ultrasound Sensors have a capacity rating and are allowed to be placed in "cyberlimbs." Presumably cybereyes are included in the term "cyberlimb" as any replacement of a body part by cyberware. Again, not something explicitly stated (as far as I'm aware), but a reasonable interpretation and one supported by this particular sample character.
So, while the characters may not be useful for modeling an "efficient character build" off of, they're certainly useful for interpreting the character creation process and rules.