https://www.youtube.com/watch?v=JiEHWy72d3w
Froch himself admitted to swerve GGG like the plague, not saying he was afraid but he definitely knew GGG could hurt him.
Also you're forgetting that GGG past his prime arguably won both fights against Canelo (definitely the first one, 2nd was close but I still edged it to GGG) who is at his peak right now. I do agree its tough to call given the weights and all that. I have no doubt that GGG wanted the big fights but most fighters were just ducking him as he wasnt a big enough name at the time and they wouldnt have got much from it. BJS held the WBO hostage for a while at MW and Canelo could have fought him much earlier.
I just dont think Froch could take a sustained beating from GGG over the course of 12 rounds, and Froch can obviously fight back but my god what a chin GGG has. He took a Canelo shot flush to the face and it looked like it didnt even phase him, and Canelo can definitely punch.