I believe it would be worthwhile to temp alias herm to femherm to transfer current content as it's likely mostly accurate, than alias herm to a disambiguation. As people tagging maleherm on posts aren't technically wrong when they tag it with herm, though it only gets the tag changed to maleherm if someone catches it. I think that changing it to this type of tag and disambiguation would make mixing of the tags less likely, and thus the site more organized.