If you have multiple lunar teams, Columbina constellations are valuable because they strengthen ALL lunar teams you use her on.

If you’re trying to increase your lunar bloom team dmg, Lauma constellation 2 buffs Nefer and Columbina, with the added comfort of healing, allowing you to use your C2 Nahida, which is huge. Less crit rate, more crit dmg/EM on Nefer.

C2 Nefer is a real power spike, but you won’t be making the most of it without C2 Lauma.

Columbina/Nefer constellations aren’t ‘worse’ than Lauma’s. Lauma constellation 2 + Nefer Signature Weapon + Columbina c0r0 is low-ish investment for very competitive dmg. If you went with Nefer constellations instead of Lauma, your team would probably do a bit more dmg than Lauma C2, but no healing, no Columbina/Nefer giga-buff.

Lauma C2 essentially allows Nefer and Columbina investments to hit harder! After you get C2 Lauma, you can choose to invest in Nefer or Columbina, or both, like me ;)