I don't know if RJ hit harder than Triple G one punch vs one punch. BUT, what made Jones so deadly was the punch his opponents didn't have that split second to anticipate . Like it took Arguello and Chavez a lot longer to stop Bazooka Limon than it took Hector Camacho. Yet of those 3 that stopped Limon, Camacho hit the lightest. I see Jones stopping Canalo because Jones offensive speed made him so dangerous.
I think Jones' short tenure at 160 causes people to underestimate how hard he hit at the weight. Look at what he did to Tate. Wiped him out with one shot - and this was the same Tate who was never stopped in any other fight in his career, and who went the full twelve (taking a lot of leather) with Julian Jackson, who's often cited as the most devastating Middleweight knockout puncher of them all. It might be down to a mixture of blinding speed along with power, rather than just heavy fists and brute force like Golovkin, but I'd say Roy as a puncher was easily in the same class. And as an all-round fighter? Different planet. Roy would have used Canelo's head as a speed bag.
It is worth mentioning that no one said that Jones hit like a heavyweight... Or at least to my knowledge.
So fighters can't have one night off? SRR, Duran, Ali, Tyson etc etc they all had their off nights Mark. He wiped the canvas with Griffin the next time in just seconds and you still found room to criticize. Technique isn't the be all and end all look what he did to guys like Toney.