Pretty much. :P Retainers are known as "slaves" for a reason dude. I never understood why we don't have buildings for banks and for setting our stuff on sale. Some poor guy/girl has to carry around all the rocks I've mined between 1-48... I'd be surprised if that sassy catgirl wasn't plotting against me at this point lol.
As for ventures, I guess it makes sense that an NPC does it. If they made the beastman mercenary services available from a predetermined location, with their own special currency and a cooldown attached, it would be similar to ventures. Going to the Vanu camp, talking to someone and giving them currency would then allow that NPC to help you for a while, with an hour cooldown. Just seems more immersive that way than being able to summon them anywhere, from my personal point of view. The OP didn't actually mention how it would work in practice so I assumed they meant it to work like chocobos and not like retainers.
Oh! I have an idea. On top of the NPCs being able to fight for you, there could be NPCs who buff your gathering or crafting too. 5% chance to yield an extra item when gathering, 5% chance to refund materials when crafting etc.
