Welcome!

There was someone on here a couple years back with an app for gear listing. I checked it out and set up an account, but can't find any info right now. I just use an excel spreadsheet. There are a lot of gear lists floating around on the internet (including the front page of this website). I haven't found any of them particularly useful because they are not set up for where I hike, the duration of my hike, my skill level, and my risk tolerance. You can check out a few to get ideas, but it sounds like you have a pretty good idea of what you are doing.

Interestingly enough many people (on lightweight backpacking forums!) recommend not having group gear. The idea is each person in the group should be autonomous in case someone gets separated they are not missing key gear. I hike in small groups (my family or close friends) so I tend to ascribe to group gear to varying degrees.

What I have found is that tents seem to get heavier per person if you go over 2 people in a tent. The one exception to that is the Tarptent Hogback which is 1 pound per person if you stick 4 people in it or 1.4 pounds/person for 3 people.

I don't backpack with an axe and I am surprised that anyone would choose to. If I can have a fire I collect downed dry branches and break them up with my feet.

Kitchen gear is another thing that doesn't seem to scale well with big groups. In the end of the day big pots and stoves are heavier per person than individual gear (or small groups: 2-3 people).

I have found you can save significant weight in food for groups if you do centralized planning. If food is a community item people will pack less "what-if" items. If you do this you want to make sure you pack enough food for everyone but you don't need to pack as much extra because you are all in it together.

If I was to organize large groups like you are doing, I would break it up into small groups of 2-4 people that would be autonomous. I would provide guidance on what to bring and what not to bring. People new to backpacking will pack their fears and end up with a pack too heavy to get up the hill.