"Meaningful reigns" - Sting overcame the nWo, in the process galvanizing the whole WCW roster that the war wasn't lost. What meaningful reign did Hart ever have? Sting's most famous for winning World Titles against Hulk Hogan and Ric Flair, Bret is most famous for losing World Titles to Shawn Michaels.
Sting overcame the nWo? If by overcoming the nWo you mean getting pinned in the middle of the ring at Starrcade (even if the whole Bret thing overturned it) and joining the nWo Wolfpac only to be taken out by Bret Hart then yeah he sure overcame the nWo. Who did Sting lose the title to? Savage, an nWo member. Did Sting ever get that win back? No. He didn't overcome the nWo that's bullshit and his his HUGE match at Starrcade helped cripple WCW, it didn't do that company any good, at least the Montreal Screwjob helped WWE in a huge way when they needed the help.
Bret may not have had any huge title reigns (its not like Sting's were anything special either) but he had some big moments, big feuds and Bret would often overcome numerous obstacles to be on top. Even with guys like Flair putting over Sting huge, even with how much Sting was protected in the early 90's he never got as popular as Bret did at that time.
Sting had his big moment when facing Hogan, but it ultimately did nothing for nobody and caused much more damage than it did good and nothing he ever did before after comes close to what Bret did when he was on top and main eventing Summerslam '92 (like Bret did) is pretty damn good business.
"Sting didn't draw" - Hogan faced many, many opponents as a face and a heel. When was WCW most successful? When he went up against Sting.
When did the WWF wrestle control from WCW in the Monday Night Wars? When Hart joined the nWo (1st time) and when he was repeatedly screwing Goldberg (when WWF passed and never looked back).
Sting did draw....... when he had a bigger draw to work with, all of Stings biggest feuds he wasn't the top draw in that feud. Sting did draw with Hogan, big time, but the nWo was the most popular thing in wrestling at the time as well and the nWo is what ultimately got the WCW over WWE, NOT Sting! You know who another face that drew well during that time? DDP during his feud with Savage and it was DDP turning down the nWo that did it, he wasn't a second thought before then. Usually its the faces that draw, this isn't one of those times. In Sting's biggest feuds/moments, it was always the heel doing the lions share of the drawing.
"Sting's more physically drained than Hart"...
! Sting has had a week to recover from facing a cruiserweight. Wrestlers perform night in, night out and Sting has worked programs against Flair, Vader, Hogan etc. I think he'll be just fine physically.
El Santo is one of the most popular wrestler's in the history of Mexico and Sting also had to fight Baba (by no means a small guy) in the round before that. Bret's matches have been pretty much all blowouts too which suggests he's gonna be in better shape than Sting. All things considered its wrestling so its not gonna matter much however it would still go in Bret's favor.
Overall I think both guys are overrated but Sting is much more overrated in my eyes than Bret will ever be. Sting was a great wrestler but he wasn't a great wrestler on his own, he often needed a leader, Bret Hart is a leader.