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I think these options can only point to NPCs with unknown skills so there could be other NPCs available to hire within range that won't be highlighted if their skills are already known. It makes sense to use these options where there are a lot of NPCs of the type you are interested in (e.g. see sidebar for zone, or station dock menu to check platforms or station population).
Personally, I don't think the time involved in finding skilled employees via smalltalk is particularly worthwhile once we start of have more than a few ships or stations but it's a mechanic available to us and different people enjoy different things. If I want to find well-skilled NPCs in a vanilla game after gaining some wealth, I tend to just mass-hire random NPCs and put them to work to see their skills that way (firing them if bad).
Collecting Training Manuals
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