We clearly can protect pages to be changed by some users. However is it possible to limit some person (1) to edit only some page (ArticleHolder type) but not to change its type, to create children to this but no other page, and to limit those pages to be of ArticlePage type, and not to create children of those children.

Surely allowed_children helps to have a correct page type selected as none of prospective editors is a malicious hacker but some are resourceful idiots

Any suggestions how to protect the site from human error?

Thank you in advance. Victor