Bev, I like your ideal. We have to go with what we know now, and sometimes there is missing information that we would prefer to have.
When I'm categorizing, I try to include what I can, even if some information is missing. For example, I know someone served in the Army during World War II, but I don't know their dates, unit, rank, etc.
Adding the sticker, or just the category [[Category: United States Army, World War II]], will put them in a grouping, which someone can later work on to fill in the missing gaps.
If people used the stickers, it would add them to the appropriate categories I mentioned above, even if some details are missing.
Stickers seem to be the easy way to accomplish this, rather than explain all the category options to everyone.
Maybe we could focus on the purpose of stickers and encourage their use. Then a future challenge could use that main category to find those missing details.