Do a lot of experts track results? In my experience, no but I don't often look at consensus rankings or positional pick lists.
How would that even be scored to determine accuracy? If I rank 32 QBs do I get a point for each QB who finishes above a QB I ranked lower? Do I really deserve a point when Josh Allen finishes above Jacoby Brisset & Tyler Heinicke?
If I rank Kyler Murray 3rd and he finishes 4th is that a fail?
Judging success & failure of ranking actually seems pretty complicated, with plenty of opportunity to overstate success.
And that's before we even try to factor in different scoring systems & roster limits which adds infinite more complications.
The best I can offer is the WDIS thread I am running each week. I track all my either/or recommendations (only those involving two players, not "pick 2 of 5" type scenarios for the reasons stated above) for a given week, then in the following weeks thread I post how many I got correct, according to my specific league scoring rules, and how many a coin flip got correct. Right now the coin and I are neck-and-neck.
All that being said picking Lance over Herbert seems like an obvious mistake of overthinking a situation.
To be fair, Lance ran the ball 16 times (and passed it 29) so the opportunity to exceed Herbert did exist. Herbert won't outproduce Lance every week but he should most weeks.
Thank you @Chaka you're getting into a(nother!) huge area of discussion. What makes an expert "good"?
In my experience, it's way more subjective than it likely should be. The guy who missed on a ton of players but correctly identified the guy who broke out is seen as awesome.
And the guy who got lots of things right but went against the grain on a player and ranked him low when he did well is a guy "who doesn't know what he's talking about".
It's a challenge for sure. And I still haven't come up with a way to grade I feel great about.