That sounds logical. There is a difference between a forum post (which is usually short) and a wiki article (which is long or even very long).
For XenForo it does not matter where the editor location is because its easy to reposition. For vaultwiki it scroll a long way down making the user loose its orientation. That being said, its probably not something that can be fixed in Vaultwiki. And not something that needs to be fixed in xenforo.