I never acknowledged Mustard as a "super producer". I personally don't think he's been around long enough, but definitely on his way. Lil Jon, IMO absolutely. Alchemist, not so much, not enough hits(mustard has more already)and even in the realm of "real hip hop"(that doesn't mean shyt when talking "super producers" IMO), he doesn't stack up to guys like Primo, Just Blaze, and Pete Rock who I'd consider the lower tier in the realm of "super producers". It has nothing to do with my opinion of them or my opinion of their music, but the impact they've had through music.
Being that "super producer" is not a definitive word, opinions will vary on what one is. I believe to call one by such a title, they should have left a wide body of work over a period of time that holds a place in people's hearts to this day. Flash in the pans need not apply. Again, all opinions, but....super producers in my mind include Dre, Storch, Timbo, Teddy Riley, Lil Jon, Quincy Jones, Foster & McElroy, Max Martin, Dr. Luke, Jimmy Jam & Terry Lewis, LA/Babyface, Rick Rubin, Kanye, Neptunes/Pharell. Guys like Primo and Pete Rock make the cut by the skin of their teeth.
Runners up who don't make the cut IMO include Jeff Bhasker, my all time favorite producer Mike Dean, Cool N Dre, Heatmakers, Tony Kanal, RedOne, BM Cox, JR Rotem(really close though), Mike Will Made It(who has time to do more and change my mind on him), Zaytoven, The Runners, Danjah, Justice League, Erick Sermon(really close, but, nah)...J DILLA(even though I can accept the fact most will consider him one after his death, in life he was not).
Again, all just opinions, I don't think I'm intellectually superior to a guy who says Mustard deserves to be on that list as i'm sure most people will consider me crazy for guys I left off mine purposely and acknowledged they don't make the cut. I don't even like music from alot of guys I consider "super producers", I recognize their longevity, their range of quality across different genres, the ability to catch the attention of fans, ect. Has nothing to do with how intricate a beat is or if I liked the song.
IMO, "super" is a powerful adjective. If I asked you to name "super humans", I'd expect alot of great people to be weeded out the same way I do when I say "super producer".
As for my comment about producer's salaries...you know what, never mind, you must've "been doin' the education" on that one...with google and all. Lol.