They're two very different fighters. But what Canelo has that Hearns didn't have which will serve him well against barkley is an iron chin. Hearns couldn't handle the smoke Barkley brought.
That's Funny, I'd like too see the same form Canelo, at least your point about facing opponents not tailor made for him.
To be honest, I don't think there's an opponent worse for him than Erislandy Lara. A negative southpaw with quick feet should be awful for a steadfast counter-puncher whose slow of foot. Canelo did fight and beat him (although not on my card, really close fight that). Trout is another guy like that who he fought and beat (again, not on my card). He was also looking to fight Plant, who is in a similar mold to the above, although not a southpaw.
Canelo is a front-foot counterpuncher. He thrives on fighters being stationary or coming forward. He definitely beat Trout (although it was close) & the Lara fight could have gone either way - although it was a bad performance from both fighters (Canelo looked bad & missed a lot, but Lara was constantly running).
Canelo fighting on the front foot is quite a new development. He didn't do it as much before GGG II, certainly not effectively at the highest level. If you look vs Jacobs, he still prefers to sit back and let people come to him. Very reminiscent of Toney in that regard. Nowhere near as good, but similar.
Hearns beat guys Barkley could never beat. But somehow the style of Hearns was good for Barkley. It happens at times. Norton for Ali. But Barkley never had a string of wins which proved it was anymore than a good style matchup. Hearns proved he was great with the guys he beat. Even the Virgil Hill fight. And Virgil Hill is a guy who beats Barkley easily with that counter hook.
You'd have to make Canelo the favorite but I don't think he gets Iran out of there, it would require a lot of exchanges with Barkley and he don't want that. A prime Barkley is more dangerous than that shot version of Kovalev
I don't know if anyone's gone there yet but I wanted to do a joke about Alvarez turning into A Flock of Seagulls and having to get on his bike and then like in perfect English going "I ran so far away." with a sh(t-eatin' grin on his face and taking a decision he didn't deserve.