Someone seems salty lolHow else do you suspect the big clubs (ie. rhymes w/Spammers) get away with it?
It's a rule, so no club is "getting away with it". Not only that, what club doesn't want their full/best "A" team playing? Sometimes people get injured or go on vacation, so nearly every club benefits from the rule especially since the majority of clubs now have more than one same age group team or probably can pull up. This provides a great opportunity for other players to showcase, and if anything is better for the opposing team given team "A" is likely at a disadvantage.