Forgiveness not permission
A critical wiki best practice is forgiveness not permission.
Wikis work primarily because there is no friction, anyone can edit. Any interference with this, and, the benefits are drastically reduced for even a slight reduction in openness. Since wikis include revision control and permit instant reverts of any bad edit, permissions are unnecessary.
Those who cannot trust even their own colleagues and employees to follow some reasonable social protocol to edit pages are known as a Pointy Haired Boss. Only this type of boss would require technical permission structures. Such structures amount to a pre-emptive sysop vandalism, preventing a good edit even from being seen. This is of course the objective, since it would challenge the power of pointy.