I dont think tests to become a moderator should be standardized. I mean someone may just be lucky or just be good at solving tests, but in general would be a lame staff member. In general, to become a member of the staff, there's a long way , they're keeping an eye on you , how you behave , how you help people, do you get frustrated , are you polite etc, even without yourself knowing, they may be watching you.
Obviously myself never being a staff member, and obviously not one who's recruiting,i dont know their shady secrets of recruiting, I guess they have their time tested methods that are pretty good.
Im against making it simpler to become a staff member. Who's dedicated will stay dedicated.