When Michelangelo got the commission he was an extremely skilled sculptor but initially lacked familiarity with the complex fresco technique.
He also had still in mind the project of the tomb of Julius II and it’s believed he wanted to delegate a large part of the pictorial execution to assistants.
Michelangelo got a Florentine friend that he trusted: his name was Francesco Granacci.
The 2 artists had studied together in Ghirlandaio workshop and in the garden of San Marco, that Michelangelo eventually entered thanks to Granacci's advise. Granacci never begun a very renewed painter.
He was unambitious, an easy living man and had a relaxed temper. In fact he specialized in less important decoration as theatrical scenery, banners for churches and knights, triumphal arches for parades.
Granacci’s lack of desire for glory was engaging for Michelangelo. Granacci easily acknowledged his supremacy, there was not artistic competition.
He entrusted Francesco Granacci to recruit the assistant he needed in Florence.