Wrong. They employed the Hell's Angels because they had before - in Hyde Park. You haven to understand the differences between the American Hells Angels (wild crazy meth-bears), and the English version of the Hell's Angels (tame, biker folk). THAT is what went wrong. The assumption that the Angels were a relatively non-violent group in the States capable of performing security at a concert. They also paid these drugged up fuckers with beer. Mistake number 2.
The Stones may have been considered "anti" Beatles by the press, but they were not, if you examine their music, very "anti" Beatles. They were a blues-based RnB pop group. Beatles had their basis in doo-wop and soul, as well as mersey beat pop. It's just a difference in vibe and background, not actual musical antithesis or conflict.
Also, DSOTM will not be the greatest selling album of all time. Unless it can move another 65 million, (2.5x) it's current measure, it's not gonna make it. I don't think it can, especially with MJ's still going.
I put the STD in STUD, and all I need is U!