I can think of several reasons why they do this, and all still comes down to winning league and cup titles
(1) they can have a side team that competes in association tournaments only and then they replace that team with their main team at the end of the season in order to earn tokens

(2) they can have 2 or more teams in the association and they use these teams to tank the league and therefore gain strong players to give out on loan to the rest of the association thereby strengthening the association.

Everything is still about earning enough tokens for the main team to compete in the actual competitions through the effort of a side team .

The only way to stop this is to stop rewarding the world top hundred altogether and also reduce the amount of tokens earned in all association divisions, instead channel those tokens as a reward to the top 8 teams in the league