Given the top 7 are all from around the same time, perhaps the effect of playing in the 80s is more pronounced than you give credit.
Ok, I will say it again using different words.
Considering the top 7 are all direct peers, just look at the
order they finished to see where Francis ranks among his peers. And consider that #1 was Wayne Friggin' Gretzky. Set aside the fact that it's an all-time list, and it still performs the function that you're seeking.
Basically what it means is, in a Gretzky-less league Ron Francis would have been the #1 most productive assist man among his peers. Never mind
league history, which unto itself makes anyone a first-ballot lock of epic proportions. He was the Joe Thornton of his era, plus defense, plus Cups, plus being highly respected as a leader, plus playing at a high level for over 20 years and being just shy of a PPG at age 40.
Once more, I will re-state that I never said Francis was worse than Datsyuk, 80s bias included.
And in case it hasn't been made clear enough already, I will re-state that Francis is head, shoulders and nipples over Datsyuk when it comes to HOF consideration. Datsyuk is a controversial choice at age 32; by that time Francis had already put together a worthy profile and was just stacking onto it with consistency and longetivity.
As for Datsyuk and Savard, it's not like Savard sucked as a kid. Other than his rookie year, he's been quite good. Perhaps Datsyuk wouldn't have turned out so good if he started sooner, maybe he'd be better. Maybe Savard needed some growing pains early to become a premier player, who knows?
Regardless of what-ifs, the fact remains that Datsyuk is in the same statistical class as guys like Savard, Brad Richards, and Spezza when it comes to playmaking centers of the last 10 years. With Thornton clearly a notch a head of the pack. That doesn't compare at all to being clearly #2 with Gretzky the only guy ahead.