That is the question.
Right now it's all in one pool.
So the question is: does the sum of all reward shares of all champion players over the season make out more or less than 30% compared to the overall reward shares of all players over all leagues.
Ask the same question for every league in relation to the table above.
If that question is answered we can compare the two systems objectively. Minding that it is based on past numbers from let's say current season and these numbers might change with players/bots changing behavior.
Those numbers are available to the dev teams, it would be good, if they were made public.