"He's only topped 13 TDs once" is about the silliest thing I've seen you post, considering that he's had exactly 13 TDs four times. Did you forget about multiple endpoint fallacies when they made you staff?
Here are the list of RBs with 5+ seasons of
more than 12 rushing+receiving TDs (choosing the other side of the endpoint):
S.Alexander (5)
M.Allen (6)
J.Brown (5)
M.Faulk (5)
A.Peterson (5)
B.Sanders (5)
E.Smith (7)
L.Tomlinson (8)
Since, excepting Alexander, everyone else on that list is in the HOF, or will be, I think it's safe to say that Peterson historically scores TDs as well as the greatest RBs in history.
No, I didn't forget about multiple endpoints. Yes, I deliberately gerrymandered the cutoffs, completely aware that Peterson had scored exactly 13 a bunch of times. No, I don't think this is unfair. Your list would be totally relevant if we were going to guess who had the most points over a lengthy span, but we're talking about who is going to lead the league in fantasy points over ONE YEAR, and Adrian Peterson's touchdown totals for his career suggest that's less likely. His 5-year touchdown totals are very impressive, but over the last 10 years, here have been the league-leading TD totals on a year-by-year basis: 17, 20, 18, 18, 20, 18, 31, 28, 20, 27. If Adrian Peterson gets 13 TDs again, like he has in 4 out of his 6 seasons, then historically speaking, he'll probably be giving up a half dozen TDs to whoever winds up leading the league. That's going to severely hamper his chances of leading the league in fantasy points.