I have never heard any kind of discussion about who deserves credit for "stan" besides The Coli.
As for Em basically being an underground rapper, with a mainstream budget due to his whiteness, that is true. But I don't think it was too many Emcee's, white or otherwise that you could have put in his place and gotten the same results with, it wasn't JUST that.
He essentially did for the young white male, what 2pac did for the young black male which was embody their angst and frustration.
Had he signed to Rawkus and kept making the type of rap he was doing on Infinite, his ceiling woulda have been more like Mos Def and nobody would be so angry at him. But he got signed by Dre and backed by one of the biggest marketing machines...got asked to walk the line between being a pop star and a real MC, took the ball and ran with it that got people invested in who he was as a person.
Acknowledging that his sales and hype are inflated because or race doesn't negate his impact or his ability, it's about putting things in proper perspective. Pretending like there's no separation between him and Canibus is just as disingenuous as calling him the greatest rapper.