How about adding other npcs, map mobs or bosses to the hideout?

So I was in my hideout yesterday and was wondering:

I have the masters in here
I have my pets running around

But I wish [insert mob name] or [insert npc name] or [insert boss name] chilling around here too.

We could UNLOCK an option to invite certain npcs to our hideout. Maybe, once we do all of their quests they can be invited to our hideout and act as a vendor there.

As for mobs and bosses, we could get a side quest from a npc to defeat said mob/boss X times and get the option to spawn one of them around. Once in there, we could talk to the mob/boss and choose to be teleported to a special arena where we could fight them in a difficulty of our choice to our hearts content. Maybe sneak in some achievements and unique rewards as a challenge.

Sounds nice?

I mean, just look at Solaris/Lunaris hideout, wouldn't it be nice to have them around instead of looking at their statue?

OR maybe, our other characters just chilling at our shared hideout?