JacktheRabbit
Explorer
At low levels getting hit by tashas or dissonant whispers is a death sentence for a goblin or kobold or knoll or insert generic low level enemy here, so by your own admission 70% of mobs are just straight ed and there is nothing they can do. The way action economy works if 3 mobs are attacking you and 2 are totally down for even 1 turn then it's trivial to overcome the 1 still standing, and then mop up the others.
Yes, very true. An all bard party, just like any other party can steamroll most level appropriate encounters if they want to. An all bard party with access to so much Crowd Control can probably do it better than most.
But what happens when you encounter the second group of goblins in a day? Or a third?