We are offered to play a match.

in my opinion, this is an amazing feature! Having 9 Phoenixes or 7-8 Behemoths on the second week is incredibly cool :)

Actually, there are no weeks with higher-level monsters; there's only a doubling of the population of lower-level monsters. And a +5 to the population of level 7 monsters can only happen at the end of the month, so it can only affect the 5th week. However, overall, I agree that this additional breeding should be banned.