Make sure the guardian wall is on the ledge close to the tree. If it's close to Stack 2, it won't draw aggro.
Keep builder squire in to build the 6th mortar at point 1 midwave, then build stack 2.
Upgrade, then run TB pull in 3 alts, final wave no DPS required.
Str drain should be right by the lower chest spawn location. If your aura isn't large enough to reach the Northern web wall without upgrading the beam, add an extra darkness trap there until you can upgrade the beam, then sell it.