you have to trick the auras onto the buff beam at north. Place auras and then place and up the main buff to 3 stars. Then run a large 6 DU beam that hits both aura stacks and up that until all auras are touching the main buff. Then sell 6 DU and continue building...
First wave, I use a tower booster and jester to up as much as i can. After that, i switch to 4 summoners and up with DPS summoner with monkey and genie.
hint 1 is 5 LT stack
hint 2 is 3 DST stack pointed N, E and W. North DST shoots down copters and takes out harbs, E agros Ogres, and W takes care of those harbs
hint 3 is where I stack my summoners, 1 guardian summoner on the LT stack and 1 on the DST stack, 1 repair summoner by the blue decoration behind stacks and 1 dps summoner with fairy and dps pet (I like monkey cuz it seems to help agro ogres on that side)
3 left over DU, I usually put a proxy on the main stack or darkness at main ogre spawn.
AFKable to completion with 4 summoners. Really have to watch where you place your summoners because they can get zapped by harbs. You will have to repair auras at south occasionally.
My builder stats: App 3k/8k/4.1k/4.7k Summoner 7.6k/4.2k/4k/3.8k EV 4.4k/8.6k/4.5k/4k Monk 4.4k/7.8k/4.7k/4k
Build will hold up MM but not afk-able