It's not really possible because only Devs and game Admins have access to the data that would help compile such a list.
Even for someone who has access to the data, how do you even go about defining a "competitive" or "active" league?
Auto kick has been removed since February so, right now, a huge proportion of leagues are padded out with inactives (people left the game months ago), filler accounts, and farming accounts.
Just look at the HoF, then check recent results for the leagues in which the "top" players compete. They are fully populated, which would seem to indicate an active league, yet well over 50% of the teams in these leagues finish multiple laps behind the winner. One person effectively races alone, often against other accounts belonging to them, they dominate the league and get rewarded with game cash every month for allegedly being one of the best players in the game.
