Click here to see the MVP Award Shares rankings at Baseball Reference.
Guerrero ranks 39th. He won the award once and had 5 other top 10 finishes including 3 in the top 5. So he was well regarded by the writers while he played (although not the exact same set of writers who will vote for the Hall).
If we look at those guys ranked 40-80, we see that 26 are in the Hall. That is 63.4%. Here are the ones who are not in the Hall
Jeff Bagwell (1 win)
Juan Gonzalez (2 wins)
Andrew McCutchen (1 win)
Ryan Howard (1 win)
Steve Garvey (1 win)
Sammy Sosa (1 win)
Chipper Jones (1 win)
George Foster (1 win)
Joey Votto (1 win)
Dale Murphy (2 wins)
It looks like 6 of these 15 have not yet become eligible. So that means 26 out of the next 35 guys ranked lower than Guerrero are in the Hall, good for 74.3%. And he is 125th in career WAR among position players, which is very good.
Yahoo Sports has an article about his case