D&D 5E CoS - what to do with all the NPCs that want to come with you (spoliers)

In nearly every location on the map, the party can meet up with one or more NPCs that want to come with them. This is in addition to the "special" NPC chosen by the cards that definitely comes with them, and Ireena, who no good-aligned, sane party would let out of their sight. There are groups of children that need rescuing (some of whom can't be returned to anyone), good NPCs and evil NPCs that connect to other NPCs in other areas and need transportation / rescue / etc. You could easily end up with a small mob of followers, some of whom want to kill you and some of whom you need to save for major plot reasons. And nearly everyone except the children are potential combatants - "XP sinkholes" you might call them. (All the more reason to use milestones!) But even if they aren't sucking up your XP, they're still taking turns in combat and generally slowing things down. You can get players to play them in addition to their characters but that doesn't speed things up too much. (They do make excellent backup characters, though.)

How are DMs thinking of handling all this? I know my group is highly suspicious of the fortunes of anyone left "off stage" - Ireena in particular has been expressly targeted by Strahd and only the party is stopping him from taking her. Most other characters are likely to be quickly killed by either Strahd or their surroundings. But keeping a group of NPCs around is equally dangerous: they can be attacked or fall into traps or be killed by any number of area effects. So what do you do?

You could create some sort of safe house where you dump most of the NPCs; you ward it and protect it as best you can, although nothing is completely safe from Strahd and this doesn't seem like a plan that would work long-term. Plus you have some NPCs that are actually evil and you don't want foxes in your hen house.

You can drag everyone with you but they'll surely have opinions on things and pull the party in different directions. And combat slows to a crawl - or else they run off and hide, which just means they're off-stage again and easier to kidnap.

What are some better options?

I plan on just having one active NPC slot (like in a videogame) and the rest of the group are sort of "virtual". The players can choose who they want in the active NPC slot.

Reading through the book more, there's a "deposit orphaned children here" sign in Krezk and a place you can legitimately dump most NPCs if you want in Vallaki and keep them relatively safe (assuming the party fixes it and it also doesn't get destroyed). So there are some places you can leave people off stage and assume they'll be ok (of course, that won't stop evil people from being hired and ...well anyway, "relatively" is the key word).

It still doesn't stop you from having a likely 3 different companions, though: Ireena, Ezmerelda (the game all but begs you to take her along as well), and whoever is your "special friend" from the card reading (if it's not one of them). That's a lot of extras to keep up with.

I'm gonna put them on players. EVERYONE GETS A HIRELING!

The various good organizations the PC's interact with might also take some of these off their hands.

It's a horror themed game. NPCs should be handy to show how the next monster works...

I don't generally grant NPCs a share of the experience unless they are ambitious enough to want to learn and improve themselves, i.e. have a class and level.

And I don't use cyclic initiative so there's no problem with "taking turns in combat". If I don't want them involved, it's going to either be "everybody else Hides" or "everybody else runs away" or "everybody else Dodges". Exception: if a player tries to provoke the NPC mob into bloodlust (as has been done on occasion) it might indeed be "everyone else attacks with pitchforks", but even then it doesn't take long to roll all the attacks.

Cyclic initiative is the worst.

Right now I'm thinking the party may just have one NPC each that they roll for; that's less for the DM to do and while the DM will still likely choose their major actions/decisions it doesn't matter as much in combat. Sure they could all run and hide but some of the NPCs are clearly there to fight and it would be against their character to hide all the time. Not splitting the XP shouldn't really be a big deal, either; if you're running a game without milestone awards the party needs all the XP it can get, and if you do use milestones the NPCs don't take away from that.