What floor are you on?

It's a common misconception that you need "two teams" for the spiral abyss. That's kind of true, but only in the regard that you need 1 DPS and 1 healer for both halves.

Afterwards it's about elemental reactions/counters.

If you are on say floor 10 having one hydro unit for each part and venti on the team with the weaker DPS for the chamber half with the most Whopper flowers is the key.

See what I mean? It's entirely situational and having set teams actually limits your strategical depht and team effectiveness.

Instead of thinking of 2 teams as both swiss army knives, ready for any opponent.

Think of it as 8 characters but you bringt the DPS and healer + 2 elemental counters each. Those don't have to be necessarily leveld to the max as long as their element counters another.

E.g. I cleared Floor 10 with lvl 40 Xingqiu on one half, used him exclusively to break water shields. But I didn't use him for either floor 9 nor 11.

Try to be flexible and you'll be able to achieve more with less ressources.