I posted a message in the tech discussion asking if there are any reasons not to have the subpages enabled in the Wikieducator namespace and if not, could they enable it. I don't think it should be a problem since it seems to be enabled in the User and Workgroup namespaces.
Workgroup isn't actually a namespace. The "Workgroup:" bit is actually part if the title, which is why the talk page is actually at "Talk:Workgroup". This is a situation I've worked with before, and we called it a "pseudo" namespace. I'm not sure why WE has done things, but in regards to subpages, they work because the pages are actually in the main namespace, which does have them enabled.