The rule has been in place for the finals for quite a few years now.
Not sure how this is going to help the comp, except stop the clubs that dont have enough players to doubling up each week.
the original rules in place state that going through the year, if you start say, 3rds and then reggies, the higher grade is the one that counts when it comes to finals.
ZL are squads and you should be able to use your players how you like in the end...
everything comes from the meetings, the noisy ones get there way because the rest dont pay much attention to there dribble.