I was thinking it would be a really good idea to combine all the leagues. Allow me to elaborate.
With all the leagues combining, there will be more prizes more activity and best of all more fun. Seperate ppl go to just one league dividing power and decreasing activity. However one big league would perhaps peak activity and bring everyone out. All the good battlers would be leaders and it will make for a stronger league rather than all the good battlers being in diff leagues.