we have no reason to think other wize. for all I know you could just reduce the colors down to 2 and say " this is my line art"
it's not about the steps. but why do you go and put thoes really weird tones for shading. I meen, look at this:
why would you put grey in flesh tones? artistic option? why isn't it any where else?
the think is, as far as I know, and I have done automatic color reduction, to optimize images for the web and so, and I know how a computer acts if you give it a pallet, and have him reduce using dither, error difusion, or just no dithering at all.
I'm not going to say this isn't. but if this is automatic color reduction, and sometime in the future you decide to produce your own work, people are going to realise it, and in the end, you will only fool your self.
belive me, you are not the first to try something like this.
if not, if this is really yours, I'd drop the weird antialiasing, it confuses people!
really, I hope you make up your mind.
Kaz