i am only using my sapper - wugu for CM mode and on maps with no flying mobs. hence i tried 2 of the best for spots with very little space. youll be surprised how this combo performs on confined space. However for general gameplay i wont use this as you stated it lacks enough dps for flying things although i can manage.
a - wugu falcon - ??? is good as wugu dont require specific weapon. before i made it a sapper its a wugu falcon mergen . though i cant clear stage 6 solo with mergen so decided to mix my two archer builds.