Hint (1) - Tower Stack the Mushroom Spore and Forest Golem so they are as far south as possible (Can't place on the bridge but you want the tower stack as far south as possible)

Hint (2) - Single Lightning Tower is enough to clean up the small trash spawns. Since we can't afford gas traps it does a great job at cleaning up the non flying mobs that focus the crystals

Hint (3) - Each Arrow Represents the leading edge of the 4 Cloud Towers. Aim 1 Cloud Tower so the Pointing North the left edge just barely goes under the bridge [Black Arrow]. Aim Cloud Tower 2 so Pointing North the Right Side Barely clips the Bridge Support so it can nuke ogres coming down the Northmost Spawner [Green Arrow]. Aim Cloud 3 so when Pointing South it's range just barely clips Cloud Tower 2 (Dijinn and Copters come down between the lowest spawner and the bridge support you spawn in so you want to just barely clip it [Blue Arrow]. Aim Cloud 4 straight South to handle the ogres/wyverns/dijinn that come in [Yellow Arrow].

If you start with Stack/Hint (1) as far south as possible, then squish Hint (2) and Hint (3) as tight as possible a 4 DU Buff beam should easily cover all towers. It also lines up so the 2 Wisp Towers can go under the North West bridge and nuke the incoming Copters/Wyverns/Dijinn.

Also lost a few runs 38-40sh when I tried adding in summoner meat shields and found that if a clear path to the 

I used a ~6k Tower Boost monk standing left of Hint (2) aiming north. With Madness Boulder Toss I aimed high towards the northmost spawner and angled it so the left most boulder would bounce off the the stone rise the spawner path is attached to and literally bounce back over my head. If angled correctly it will literally bounce up the lane straight south where the last of the ogres and dijinn come in and keep a near 100% uptime with a 30k genie and 10k boulder ticks.

Worked very cleanly with 3 summoners, 2 Huntress, 2 Monk, 2 Apprentice all stacked around the Lightning Tower in Hint (2).

Final Note. Hint (4) Reflect beam needs to be precise. Ogres from the the spawner on Hint (2) will toss snot when they get slowed so you need the beam to be angled to just barely reflect it. Likewise, the beam also needs to catch the wyverns coming from the south aerial spawner. It works if you place it so the bridge creates a line of sight and then you angle it as tight to the crystal as possible

Hint (5) is the same as Hint (4) but in reverse. It needs to catch ogre snot coming from the middle west spawner that go under the bridge, and also catch any loose flyers that come under the bridge. The wisps should take care of most of them, but there is a small window where a flying mob can come under the bridge and try to target the crystal. The ogres that come from the Northmost spawner should be close enough to your tower stack to target it before the crystal so no protection is needed there.

Most tower stats are floating around 6k major with 2.8-3.2k minors.