Fel Reavers were the peak creation of Engineering. Besides the complexity of their inner workings, they were gigantic. If Infinite Starry Sky was left to deal with it alone, he might not complete it even after 3 months of working. As such, he would need a group of Engineering students.
They were called students, but all of them had the same level of Engineering. All of them were level 60.
In the beginning, everyone was disgruntled. Why were they still doing student-work when they were all the same level?
Student just involved making spare parts, which gave some Engineering experience points. However, it couldn't be compared to the growth of Infinite Starry Sky's experience. Furthermore, when the Fel Reaver was complete, Infinite Starry Sky would take the credit for it as well.
Everyone wanted to have something that they were known for when learning a Profession.