So here is a visual example of what I mean.
Heres a view of my copied out and edited wardrobe array, shrunk down for scope.
The way the game saves data seems to be to be a little odd. I would think it would keep all clothing items defined under "clothes" but then use references/etc in the outfit groups, but it doesnt do that.
It seems the first time a given object is used beyond its standard category type (in this case a clothing item), it moves the entire array of the defined item into the outfits array, and in other cases it will leave the ref ID# identifier as it may be fully defined elsewhere.
You even see elsewhere in the save files for the other ref ID#'s for characters, if your character gets pregnant, the father ends up being a part of the sub-array of the pregnancy inside the PC array, and then is left as nothing more than a ref ID# in the larger malenpc array. I just figured, the main arrays would have stayed static, and then ref ID#'s would have been used everywhere else, but again I dont know coding that much and really dont understand java.
Back to clothes..
In this example the top item is fully defined in this outfit grouping - hence under the actual clothes category, it has just the ref ID#.
The rest; the bottom, bra, and legwear parts, since those 3 pieces are defined elsewhere, also have just the ref ID#.
It does seem that only completely unused items end up staying fully defined in the clothes section.
So when you go to start editing, if you add something completely new especially, need to make those ID#'s unique and make sure that any defined outfits have their ref #'s updated as well.
So this snip here i went and added 30 to the beginning of all ID#'s, so then i can take this and replace the entire wardrobe array in any new game I start once you can do that initial save, and then reload that and continue on. The game never starts with much more than maybe 100 some odd ID#'s unless you go crazy with starting wardrobe choices or crank up your NPC generation.
I just added 30 to make sure any intial single digit IDs were at least extended into the 300s, and any double digit ones into 3000.
Game doesnt seem to care how high it goes, but once you load that save and then resave it, it re-sequences the ID's on its own, so the number range will be all different afterwards.