You need the latest version of Switch Toolbox and your dump. If you like to do texture modding, click the link by KillzXGaming for a quick guide(Pretty much texture modding in SwSh is pretty similar or identical to Let's Go).
1. Pokemon:You can find pokemon models on romfs\bin\archive\pokemon. Names are based of the National Dex index except for Kalos to Galar which is a big mess.
X - Pokemon number
Y - Different form (Gender, Regional, Alternate forms, Gigantamax)
I will talk about this below
pm0003_00.gfpak - Venusaur (Male)
pm0003_01.gfpak - Venusaur (Female)
1.1. Forms:Now since Let's Go(I don't know for the 3DS titles), pokemon with different forms still belong to the specific dex number whether it's male or female or Mega Evolution or Alolan form.
pm0052_00.gfpak - Normal Meowth
pm0052_00_31.gfpak - Galarian Meowth
pm0052_61.gfpak - Alolan Meowth
pm0052_81_00.gfpak - Gigantamax Meowth
pmXXXX_00 - Male/Default
pmXXXX_01 - Female
pmXXXX_00_31 - Galarian + Galarian Evolution
pmXXXX_61 - Alolan
pmXXXX_81_00 - Gigantamax
pm0025_18 to 24 - Ash Hat Pikachu
pmXXXX_11 - Original
pmXXXX_12 to 28 - Alternate forms(Cherrim, Shellos line, Rotom, Basculin, Darmanitan, Kyurem, Keldeo, Aegislash, Pumpkaboo line, Wishiwashi, Silvally, Mimikyu, Necrozma, Morpeko, Cramorant, Toxtricity, Alcremie, Sinistea line, and Eiscue)
Not in the data but I like to include this from Let's Go. Mega Evolution models are _51.
As I said earlier, Kalos to Galar pokemon are a big mess because their number is not based of their National Dex entry. Not sure if it's the same for the 3DS but it's weird and off. It's difficult to find pokemon model from Kalos to Galar and the only way to find out is to do it manually.
Phantump(#708) is pm0702_00.gfpak and after Black Kyurem (pm0647_12.gfpak)
Bunnelby(#659) is pm0711_00.gfpak
In theory, I think pokemon from Kalos to Galar is based on development or when they implement it. But interesting thing is that Kalos starts at the 700s. So maybe Game Freak decided to put them in 100s or something.
700 - Kalos
800 - Alola
900 - Galar
Here are the list of pokemon from Kalos to Galar.
Now let's go to Trainers!
2. Trainer:You can find trainer models on romfs\bin\archive\chara\data. There are four folders:
-ob - Objects(Not Trainer, just objects like bicycle)
-pc - Playable Character
-tr - Trainer
-tr_m - Trainer_Model?
2.1. Playable Character:There are two folders in pc folder. p1 is the male trainer and p2 is the female trainer.
The playable character have separated models for designing your character. Here are the list:
-bag - Bag
-base - The skeleton
-btm - Pants
-eyb - Eyebrow
-eyw - Eyewear
-face - Face
-ftw - Footwear
-glv - Gloves/Hands
-hdw - Headwear
-hrs - Hairs
-inn - Top/Shirt(Inner)
-lgw - Legwear
-lns - Eyes/Contact Lens
-out - Jacket(Outer)
-spw - Bike Outfit
If you are looking for default male or female player, you have to find them manually. Also, most of the textures are white because the game uses vertex color to color the models. Which means, it's likely possible to color your character's skin to a green Alien or Dona[REDACTED].
2.2. Trainer and Trainer_Model?:Unlike playable characters, the trainers have full body model. Although I cannot list all 138 but I can give you some of the characters. I honestly don't know the difference between tr and tr_m except that tr have more files than tr_m. Maybe tr_m is used in overworld?
tr0001_00_champion.gfpak - Champion Leon
tr0001_01_champion.gfpak - Battle Tower Leon(*plays Battle Tower Theme)
tr0002_00_friend.gfpak - Hop
tr0002_01_friend.gfpak - Hop (League)
tr0003_00_assistant.gfpak - Sonia
tr0003_01_assistant.gfpak - Professor Sonia
tr0004_00_u.gfpak - Bede
tr0004_01_u.gfpak - Gym Leader Bede
tr0005_00_EvilSister.gfpak - Marnie
tr0005_01_EvilSister.gfpak - Marnie (League)
tr0005_02_EvilSister.gfpak - Gym Leader Marnie
tr0007_00_doctor.gfpak - Professor Magnolia
tr0019_00_leagueSecretary.gfpak - Oleana
tr0020_00_leagueChief.gfpak - Rose(Outside)
tr0020_01_leagueChief.gfpak - Chairman Rose
leaves - Milo
water - Nessa
fire - Kabu
combat - Bea
ghost - Allister
fairy - Opal
rock - Gordie
ice - Melony
evil - Piers
dragon - Raihan
trial<type> - Gym Trainers
seed<type> - Gym Challengers
pc - Nurse Joy
playPokeM - Pikachu boy costume
playPokeF - Eevee girl costume
tr0141_00_mascot.gfpak - Pokeball Guy
This is pretty much it. This would be handy for those who want to do texture modding and save some time to locate what you're looking for.