It would not just be Master Yun Chi and his party traveling to Sandstorm Abyss alongside them. Master Ruo Chong would be coming with them as well. Wu Jian learned the evening before they left that she had arrived before they had. Since they had both requested a guide from the Mercenary King, he had decided they would travel together because there was safety in numbers.
That did not mean they would travel together once they reached the legacy tomb. According to the report, there was only one of Medusa’s Tears. Since they were both traveling to the legacy tomb for that, it meant they were in competition with each other. Both alchemy masters had only agreed to travel together until they reached the legacy tomb, and then they would split up.
Shā Shing Yue and the group she was leading would not be traveling inside. Their only task was to ensure they safely reached the legacy tomb.