Hint 1: Stack the auras rather than placing them in unusable space like I did here...
Hint 2: You can fit these minions around the bowling ball turrets. They fit on the buff beam with careful placing, but stacking is an option if you're having trouble.
Hint 3: I put a longer buff beam on the middle path, so it has room for a couple more archers.
Hint 4: DSTs are actually too slow to get all the wyverns, so a few archers help. Of course, if your monk has decently sized auras, they won't get through anyway.