Noah's group could skip most of the trials. They could search for the various secret passages and reach the most challenging part of the fifth layer since the hidden area was probably there.
However, the quality of the rewards had made them decide to invest time in clearing the whole inheritance. The battle formation found after the battle against the scaled sphere was only the last of the many valuable resources obtained in the process.
The weakest part of the army took a break from the trials to learn the battle formation, and King Elbas joined those assets to modify the technique.
Great Builder had already modified that formation back in the days, but he didn't adapt it to the different species of the higher plane. Noah's army featured hybrids and magical beasts, so King Elbas had to change something in the technique's structure to make the best out of those lines.