So he never had vision? Was a top runner for years on college and for 3 years on the Cowboys, but somehow he managed to win 2 rushing titles, and probably would have won another without being suspended 6 games, and yet "lacks vision"?
That's something you have, or don't, as a runner, it's not learned or forgotten. Usually if the back's performance tails off, it's because he sees the holes, just can't physically get there or break the tackle. Per above, there's no reason for Zeke to have had that happen to him.
And as far as the "he's only good with a top line", let's look at Emmitt's career, shall we?
From 1992 through 1995, he never had less than 1,484 yards, had 18 or more tds 3 of those 4 years, 9 in 1993 but he held out 2 games, and 4.6, 5.3 and 4.7 ypc in 3 of the 4 years.
Then from 1996 on, never above 4.2 ypc, or 1400 or more yards. So what happened?
Well in 1994 John Gesek and Kevin Gogan left. In 1995 Mark Stepnoski left. Tuinei left after 1997 but he had a knee injury a year or two before. Cowboys got Larry Allen, but he's only one guy, great as he was. The line was NOT the Great Wall anymore. So I guess Emmitt lost his vision, got fat, got satisfied with his contract, etc.? Does anybody that watched Emmitt or heard about him think that? Certainly not, but that's what they say about Zeke, and the oft-heard line "doesn't matter, he got paid so he should still be cranking out 1,400 yard and 12 td seasons, right? Oh wait, in 2019 he had only 43 yards less than 1,400 and still 12 tds.
If 1,357 yards and 12 tds is poor, I'll be glad to have it...