No global solution . Some ideas
1) I will take away the perm wiki_edit for registered and I will activate in admin -> wiki "Page creators are admin of their pages:"
Like this only the creator can change his page
.... but nothing will protect someone else to create a page from a wikiword of the page of another user (if wikiwork enabled)
2) perhaps one categ / user.... In 1.9 the quick edit module used in a wiki page can control the categ inheritence...
No real good idea