Large organizations which have money, power, influence should have a communal pool of maybe about 3 well statted, well geared bodyguard NPC's. Ideally these should be using memento loot code so that there isn't an incentive to just use them as loot troves, and instead use them as a RP tool. There is the possibility to enable a lot of really neat, really cool, and potentially a lot of really fun RP using existing code. Let me lay out a few examples of things I'm thinking of.
Powerful crime family has a handful of powerful, influential PC's in it, but they play at differing times, some are on vacation or unable to RP. This leads to a situation where the under-staffed families sometimes feel, or are, permanently camped for the loot and prestige of killing them. What if they had 2-3 really solid NPC's in their HQ that Family member X could ask to bodyguard and walk with them? Now instead of just being easy pickings, there's an actual tangible risk to engaging them because they are member of a powerful organization.
Megacorp has a security team with a few NPC's in it that are perhaps better outfitted than your normal hall monitor guard. Players of a certain rank should be able to task these NPC's out for the basic grunt work of taking bullets for some high-level suits or talent in their organization. Either because their players are not specced into combat, or because the 'good' combat characters are not available, as mentioned above (taking break, schedule conflict, etc.) Now the talent or manager can go visit potentially dangerous places and RP with different sorts with some level of confidence that they aren't going to get slam-dunked without tangible risk.
Now, the limitations are really what would make this from a overpowered problem waiting to be exploited to something that could be more interesting. Without going into super specific details, I'll mention the following things that should be considered:
(In no order)
1) NPC bodyguards shouldn't be lootable, rippable or otherwise setup in a manner where someone leading them to be 'accidentally' necksnapped winds up in any currency being generated or moved.
2) NPC bodyguards should have the basic code options that existing NPC's with this function have: Verbs of: Follow, guard, attack, enter/exit vehicle, stay, etc.
3) There should be OOC rules for their use similar to what other coded NPCs with similar function have. They're guards, not people for you to have murder whoever you want, be used to do unthemely things, etc.
4) They should have gear befitting someone whose job it would be to guard their respective PC's. Not top tier stuff, not garbage. Attention to be paid to weapons as well, as some would be better suited for this sort of thing than others.
5) They need to have protection from very easy to access, cheap methods of getting 'free' necksnaps.
6) Probably should have a max duration that they can be taken out for a whole bunch of reasons.
Ideally, if it would be possible, just make them actual mementos that the people with access can call up dynamically, and just set a fixed despawn timer. Maybe add a voice line or two to the guards along the lines of "30 minutes sir, before the next shift change." or "We have urgent business back at HQ in 15, we should get moving." At the end of their timer they just exit existence like every other memento.
Add solid bodyguard mementos you can spawn as a member of large or powerful organizations and roll around with for X amount of time. Give them some actually solid gear (not best in class or close, obviously) but they should be actual threats if you get them on your character. Have them despawn and be unlootable so it's not an invitation to lock them up in random places or to treat them like vending machines. Give people who can be trusted (read, been with the org more than 2 weeks) access to them to use as they see fit. If they abuse them, take them off the access list and slap them ICly for wasting org resources. Otherwise let a player or players use them as they see fit, just so long as some common sense OOC rules are being adhered to.