It was leaked internally by one of the managers how much is the share of each talent.

Some Talents like Suisei, Marine, Miko and Korone, were very aggressive when it came to renewing the contract with Cover, thus Cover accepted their terms and thus cover got a lower cut of their total profit. And thus they got a much better deal than the average talent.

Miko only pretends to be dumb, but she is pretty smart when it comes to business stuff.

Others like Aqua, Fauna, etc... they didn't like it at all and wanted the same deal as Suisei, Marine... had. But Cover didn't budge one inch.

Thus many left.

Others like Pekora didn't care that she was earning less than a few others.

Nobody said a word about this, because it would be automatically a breach of their contract if they did.