Actually, there are no weeks with increased numbers of high-level monsters; instead, there's a doubling of the population of low-level monsters. And a +5 to the population of level 7 monsters can only happen at the end of the month, meaning it can only affect week 5. Although, overall, I agree that this extra spawn should be banned.
Not long ago, I played with vbn on a Conflux map. In the first week, I placed birds, and the second week was the Firebird week! We agreed that I wouldn't just buy out the 5 birds that appeared as a result of this week. It's hard to imagine what could be used to counter 9 birds on level 121.
