User blog comment:Darkcloud1111/The Bigger Story Behind the Story/@comment-11188061-20141019082638/@comment-3146930-20141020010845

Leading to the surviving Grimm becoming more and more powerful each time, leading to a more difficult time for the Hunters later down the line. Hit and run tactics are nice when used effectively, but we are talking about an enemy that literally covers the planet. That is like taking the world's four biggest cities and having the population of those cities fight off a zombie outbreak that has overtaken the entire planet. Plus within the walls of these cities, it is clear that not everyone is a fighter and we haven't even seen any type of military outside of Ironwood's crew. If all it took to defeat the Grimm was a series of ambushes, I'm sure someone would have done it by now.