Your team roster should include a few builds, one of which is your dedicated weekly farmers.

Metatron/Echidna/King Shynee/Angelit/Valkyrie in that order should be your last team. That order facilitates; you use all monsters in sequence left to right and are guaranteed to hit everything you need to win (as unicorn is the furthest right monster and is hit last). My own is just opposite, as I lead with unicorn, and doing it this has reduced my fumbling to absolutely zero. Before that I've had several issues where someone didn't happen right – Valk then angelit, or no shynee, or hit shynee instead of Valk on an earlier wave... Yeah.