These two are close enough that you could go either way:
Hernandez also has the “greatest defensive 1B” case. Whether he was the best or not, his highlights make it clear he was elite. He moved like a shortstop, and if he did not throw lefty he probably would have played on the left side of the infield. He should be in.
Olerud should be in if Hernandez is, but I see why his case is weaker due to the hardware. But it's not his fault idiot writers (and front offices) didn't evaluate him properly when he played. He still has some accolades (3x GG, 2 x AS, Batting Title, 2x WS winner). He also has two 8 WAR seasons, nobody else being mentioned had any.
These two aren't there for me:
Mattingly isn't a HoFer to me. He was great for 4 seasons but in the other 10 or so he only put up about 15 WAR. It's unfortunate because it was probably due to injuries but if he wasn't a Yankee he wouldn't even be on the HoF radar. If he was a better manager on top of his player status, I could see making a better case for him.
Delgado is not a Hall of Famer to me. His talent and counting stats were close, but as a first baseman in the steroid era you either needed to be a bit better or last a bit longer. His career wRC+ was only slightly higher than the others being discussed, and his defense was much worse. If the Jays had moved him off catcher earlier in the minors, he probably would have reached the majors sooner, and that extra production might have pushed him over the line. Another one or two effective seasons at the end of his career might have done it too. He is close but not quite there, though if he gets in I will still celebrate. There are worse Hall of Famers, and it would be nice to see more Jays added. I also do not factor steroids into my HoF evaluations at all really. That probably leads me to penalize the supposedly clean guys like Delgado and not punishing the others enough.