This is a proggress viable setup that i personally used when breaking into C2.
The general strat i use for pretty much any map is 2PDT per lane, 2Flamethrowers per lane (3 if DU allows or more is needed), 1 Spike Blockade per lane and a Skyguard tower where ever needed.
Info 1: i place an "Skyguard tower" here. The PDT up north will take care of most the fliers but sometimes a couple manage to slip trough
Whenever possible i place all the "Flamethrowers" and the "PDTs" on ledges out of the main path of the enemies.