I usually use Loki to immobilize L!Azura (making her unable to catch up to the other heroes), and make my priority to snipe one or both dancers before the enemy turns aggressive.

Unfortunately I almost always have to sacrifice one hero though, because I'm facing a team of 6 with my 5, and I can't set up a reliable Galeforce team to compensate for that.

But yeah, like 90% of the teams I fight in Tier 21 AR is always 2 dancers (sometimes 3) with Ophelia, and the remainder being either Firesweep users (Double Poison Strike Brave Lyn, Siegbert with Lunge/Drag Back, etc etc), Eir, Reinhardt, Veronica (who is only really dangerous with Restore+), Aversa, and sometimes a spearhead (Legendary Hector, Surtr, or Duma).

Last season had a lot of 2-3 dancers + Ophelia + Galeforce Tibarn + 1 other, but now it's back to how it was before with beast bonus season being over.