Specialties in specialties

I've been thinking about cg artist as RPG characters. Where people are at a level, and can level up with time or study. Each artist gets good at what they are mostly asked to do. Creature modelers get better at creatures, Lighters get better/level up with the renderer they use day to day.
In FX its interesting. There are specialties within the specialty of FX. I think of it as a mage character. You get to a certain point in the game and you can choose a more specific specialty. Dark, Light, Fire, Ice Mage whatever, something. FX is kinda like that. There are Particle specialist, Shader specialist, Fluid, Fire, Liquid, Deformation, Destruction etc. FX artist will learn in these and other categories. From time to time be further into one than another. Not that we can't do them all but people's experience make some a better fit for some jobs than others, "Specialists". Maybe its more like a thief character where we keep adding to our ability %'s.
I think about how you can keep pushing in one area but your improvement slows, like each level is double the current exp points. I think that is fairly accurate from games to real life "levels". hah NERD ALERT!!!