NY, Cali, and everyone wasn't playing UGK, Outkast, or 3-6 Mafia? Jay-Z did a song with UGK 2 years before TI's first album dropped.
Of course they're gonna name those producers. They're newish. That alone will get them mentioned before DJ Paul or Pimp C.
And no it ain't gonna sound the same....again, that shyt is 20ish years old. Kool G Rap and Raekwon rap about the exact same shyt, "Road To The Riches" sounds nothing like "10 Bricks" though.
Matter of fact, let's forget all that. Let's say you're right and they popularized trap, a subgenre of rap. Do you think that alone makes them legends? Legends....among the Ice Cube/Nas/Scarfaces of the world?
Fred.
Who said all legends are created equal?its like sayin Charles Barkley,Iverson,Ewing ain't llegends cuz they don't have rings like Kobe,Jordan,Magic,Bird.....nobodys putting those guys on that level as of yet,but they are still legendary status



)
in this thread... 
at the thought of these 3...no knock on those dudes I named,id say they are legends but sum of they resumes is weaker than jeezy,ti,wayne.