How about that the soldiers could move around the palisades? Seems stupid to be standing around doing nothing although there is an empty palisade next to the guy where there would be a great spot to fire people.
Idea: Maybe I get the impossible badge if I just keep dropping the blocks on the center part as quickly as possible... *five minutes later* Idea: Maybe I get the impossipble badge if I carefully place the blocks in a logical manner... *fifty minutes later* Idea: Maybe I get the impossible badge if I just break every block before they go down... *five hundred minutes later* Idea: I think I should get some sleep now and continue later...