Flip was not a multi-platinum rapper. U Gotta Feel Me went platinum. Trap Muzik was hardly a flop. T.I. didn't really have any crossover hits on that album. Trap Muzik had street records like "Be Easy" and "24's" as singles before "Rubberband Man" and "Let's Get Away" dropped which weren't crossovers either. Flip on the other hand had the radio friendly "Game Over" and "Sunshine" as singles. LOL @ T.I. being low on the food chain. Diddy was trying to sign T.I. and Pharrell was saying T.I. was the Jay Z of the South even though I'm Serious was a commercial flop. That's big words coming from Pharrell when he worked with Jay and he doesn't even say things like that about his own artists. Flip didn't beef with T.I. b/c the beef was started over "he say, she say".
As far as the artists that were working w/ T.I., notice I said legends and mainstream artists. T.I. was featured on their records, not the other way around.
Anyways back to the subject, either way T.I.'s imprint on Southern Rap is much bigger than Jeezy's. Take away the record sales and T.I.'s commercial appeal and you still have the rapper that influenced Jeezy and all the other trap rappers after. Before T.I., artists weren't even putting "trap" in their album and song titles. Soul Food track #4 made it a concept and gave artists like T.I. a blueprint stylistically, but T.I. made it a movement. Before T.I., "trap" rap didn't have a face.
To Jeezy's credit, he came with the whole "Snowman" theme and hot the shirts that were banned and what not. Jeezy's biggest influence was him influencing artist to get DJ Drama host a solo Gangsta Grillz. Before Jeezy, Gangsta Grillz were just compilations of different artists' songs, after you had Wayne and other artists going to Drama to host their tapes.