Being an editor in a category, by my understanding he / she can edit that category, the person doesn’t have to own the category to make a positive or negative effect to the categories listing. If for example they are very few editors available and being that maybe he is the only one, would it be possible to think that he manages that category (correct me please if I’m wrong..).
Slightly wrong, but by a matter of degrees.
No one owns a category. It is as simple as that. A given editor may make the majority of his/her edits in a single category, but there is now ownership or management involved.
Case in point; I am one of the named editors in Regional/North_America/United_States.
That simple means that I can edit in that category or in any of the thousands of subcategories directly below that. There are some state categories where I have never edited, and some state categories were I extensively edit. Yet, in every single category where I can edit, there are other editors who can also edit, and every one of my editing decisions is subject to peer review.
That is the thing to remember, especially with so-called "popular" categories. The permissions represent a tree and as one moves higher and higher in the tree, the *less* likely it is that a given editor is solely focused on the category where they may have a site.
Some editors (myself included) also keep their names on categories where they have a particular interest (even a sentimental one) even though they may have permissions in a higher category that includes that one. Some do it because it may have been their first category, or because (do to navigation issues) they want to be able to quickly pop in there. Still, no onwership or management is implied -- and this is often the source of the misunderstanding that because Joe is the named editor for a given category no one else can be named. Many, many categories have multiple editors named.
can I post the category in question
We prefer to keep the forum postings generic.