Every NPC doesn't need a PC build, but those NPCs who are trying to emulate something a PC can do or be would use a PC build to get there.
The Bodyguard is clearly trying to emulate some sort of Fighter. OK, let's start at Fighter and tweak - using abilities the game already has, and gawds know it has enough of 'em - until we can create this guy.
Can't make it work? OK, let's design a new Bodyguard or Brawler class as a sub-class of Fighter and then - even if it's "underpowered" - make it PC-playable. (honestly, I think the game in fact has room for this - a mostly unarmed combat class that isn't a Monk)