I'm not sure if you know this, but there is a world of difference between the 1-6 and the rest of the super Titan on the weekly elite. I could get lucky and beat any super Titan sure, but most of the time they will destroy me. The top 10 players should be in a league of their own. It would be more accurate if they could just take torbreck, this guy always, Nagibator, gamtruly, and maybe beachlanding and stick them in their own league.
Anyway, what I'm trying to say is that the weekly elite numbers don't reflect the super Titan ranking numbers. This guy always at 13 and torbreck at 19 are far better than I am at 6. I have just played more games than they have this season. The same holds true for every other league. I know you need some way to gauge skill levels but getting the ranking a person is inside their division probably isn't that accurate.
A more accurate way might be to see if someone has played against anyone above or below their league or has steadily been in it. This isn't perfect either but it's the best method I could think of For anyone not on the weekly elite. The weekly elite should also take priority over ranking in the master league if they show up on it.
Hope this helps! If you decide to use this information and need help gathering it I'd be happy to help you! If not I'm sure it will be close enough, this is a friendly tourney after all.