The scientists didn't stay idle during the month of battles. Some monsters were processed to retrieve food and valuable materials, but the rest went to the interactive desks, falling under the scrutiny of those specialists to uncover eventual weaknesses.
Much had been discovered in that period. It turned out that Senerth's monsters could theoretically grow infinitely. They were hunting machines, only held back by their diet. The richer it was, the bigger and stronger those creatures would become.
The monsters' hungry nature and their ability to reproduce quickly worked against that incredible factor. Even in Senerth's richer areas, food was scarce, probably vanquished after decades of famished raids.