Improvements to Blitz:
1: 4 builders. This is just the standard solution. (All but the first 3 poles are safe to fall from)
2: 9 builders and 1 digger.
Dig a pit under the trapdoor and release the crowd with a basher
5: 6 builders thanks to a steel glitch, replay attached
8: 2 builders and 1 basher (not 2)
9: 8 builders, replay attached
10: 2 builders
12: 1 bomber, 1 digger (this level has no builders, so I have no idea where the score of "6 builders" came from)
13: 8 builders
15: 9 climbers, 1 floater, 1 bomber, 1 basher (see attached replay)