That is, the diversity in their experience prior to the show. Most have done work on single TV episodes and in commercials, because that’s how most actors make their living, but otherwise they come from very different backgrounds:
Joel McHale was pretty much exclusively known as the host of the comedic entertainment news show The Soup—as a TV personality and not an actor.
Gillian Jacobs came more from a theater background, having performed in several Off-Off Broadway shows.
Danny Pudi studied at Second City, gaining a lot of experience in improv before moving to LA.
Yvette Nicole Brown had worked steadily in guest TV roles for close on a decade, her most prominent role only being on the immediately-cancelled show The Big House—which is baffling. (Lala not going to rant about racism/sexism right now.)
Alison Brie was more experienced in leading roles, but almost entirely in Internet and indie film stuff that, let’s be honest, almost nobody saw.
Donald Glover spent a short time on the writing staff of 30 Rock, independently released a rap album, and got most of his performing experience as founding member of Derrick Comedy, which had/has a strong presence on YouTube.
And Chevy Chase was, of course, a big comedy name in the 80s, but his star had fallen a bit (and for a while) by the time he joined the show.
Just a thing I thought merited pointing out.