Couple of ideas

The fly swatter
New air trap similar to spring trap.
2x2 trap that swats a 2x2 air area off the board trigger range 4 tiles (two from edge of trap) max 2.

Troop AI improvement 1

if a defensive seeker, ie giant, hog rider, balloon, golem, has a 50/50 choice of going to two weapons it should target the most threatening of the two. Think of it as a slight refinement to their established role, giving them a bit more self preservation.

Example: balloon targets archer tower, cannon and air defense are positioned equidistant from archer tower, after archer tower is destroyed balloon should attack air defense.

Troop AI improvement 2

Fix the "what are you shooting at"issue where one or two (or lots sometimes) troops will shoot at a wall when the rest of the group moves to a new target when the intended target gets destroyed. A confirm best target algorithm in the targeting code would help here. Obviously something exists to cause them to switch in the first place, it just needs a check up.