No but something is nagging my memory. Something about how classes affected growth. I wanna say it was a reference to Warlocks gaining strength through their research. It reminded me of how Savathun is mentioned as being able to gain power through deception. Perhaps classes are more important then they seem on the surface.

It's difficult to have a new class type since, heavy/tank types become Titan, support/defense types become warlock, and stealth/offensive types become hunters. Since only humans (and there variants) are risen then that is a limiting factor. Mental and physical attributes have a deciding factor in which class you end up. For example (although I play Titan) IRL I have the mentality and build of a warlock. If other species were risen like a Fallen then maybe the abilities change.

No, there are only 3 Classes. Classes are just an organization system created by the Guardians of the Last City a couple centuries after the first Risen were revived. Guardians choose their Class based on their pursuits. Titans: defend humanity through brute force (offensive or defensive) Warlocks: Pursuit of knowledge that can aid humanity Hunters: exploration and discovery of means to aid humanity Edit: And your body type has nothing to do with your Class.