No it should definitely not be lineal. You need a clear top two to emerge to restart history definers, there's literally six guys there who are close to 50-50-ish.

Now currently Groves should definitely be no.1, he quite simply has competed against and beaten better fighters than anyone else, but the rest are a toss up.

I don't see much wrong with the Ring crowning the winner of the world series in this instance. In fact the winnner of the world series should become THE champion per division, make everything easy.