DM question for out of the Abyss *SPOILERS ABOUND***

[sasigns]

So in trying to figure out what challenge rating and encounters the party can take on. I have looked in on page 82 of the DMG and come up with the following
Attachment 14548

The level assumptions are based on the hit die of the NPC. The thing that I am wondering is as they first escape. I highly doubt that the party would be able to grab enough gear to fully outfit 15 people. What did you guys as DMs due to figure out what people were able to escape with and how did you adjust the party to figure out what they could handle?

[Zacchaeus]

My party started at level 3 and left most of the NPCs behind to cover their escape. I used the demon fight to distract everyone so they were able to recover their equipment. They did so and then ran for it. I think maybe 2 or 3 of the NPCs came along with them but we killed those off pretty early on too
No-one was really interested in playing with henchmen that they weren't able to create themselves - and they are all pretty rubbish anyway - unless you are deep into your roleplay and even then they are pretty rubbish