Everyone was surprised by the sudden apparition of the Loporrit. That also included the twins' group. After all, they heard from Bunbun that the Loporrits couldn't intervene with the events unfolding in this Wonderland due to some rule of the Loporrits.
In Roan's eyes, those three Golden Drohares had already escaped when that item appeared. It's not that the twins didn't want to help stop the Golden Drohares, but that they spread the net to catch the fish while they were in the midst of a battle against Wonder Beasts. It was decided from the start that the moment the Semi-Celestials acted to fight the enemies, which were the Golden Drohares, the twins' group would provide support in the battle against the Wonder Beasts instead. That would allow the Semi-Celesitals to focus on the experts that were controlling the Wonder Beasts.