Suggested

Game is bigger then individual

I think someone has to make the tough call of culling the leagues. 
I think any league that is less then half full should be given a 15 day notice fill the league or move to another league. There is so many leagues that are at the same time or start just 30min apart. Surely people. An find a league that fits them. Even get all of there friends in the league to move together.
Yes I understand some have been in the league for a long time but they should also no for the good of the game and to keep it growing this needs to be done. 
It will help the new (rookie managers) find active leagues and stay engaged. There will be more chance of moving up and down making sure if teams move up to quickly they can still drop down again and be competitive.
It will probably make it better for people in elite levels to get new competitive drivers and challenge them again. 
I also know alot will be against this coz it means they may not win everyday coz they are in a easy league. They need to grow up for the game to move on aswell.

100% agree with it.
There are more or less only afk leagues.
Sure there are active leagues but if you go through the leagues you see afk leagues everywhere.
But the ego guys hunting for race wins will cry because they have to do some work on the game.

I think that there are still lulls and we are in one for recruitment of new players.  This would help, but there are still active leagues for Elite tiers that may meet your criteria.  It may be best to specify your criteria for Elite tiers only rather than an entire league setup.  So that we can keep competitive and active Elite tiers, which is what we want to enhance recruitment of new players and others to what will become less Pro tiers in practice.

Doing this should also reduce "Farming", due to having more active leagues, than not.