I feel like I kinda had to to match the crazy THC, damage and AC of lategame bosses/enemies.
You felt like you had to since you were putting all your eggs in one basket instead of designing around team synergies. Six threats > one.
Just use AoE buffs and attack their weaknesses. Playful for instance is a Vivi and if you've ever played one you know they're a glass cannon. No Uncanny Dodge, no Mind-immunity so can be Intimidated, etc... Break the glass.
There are a good many no save debuffs as well. Short duration, but there are no bullet sponges so that's all you should need.