Giles should get picked in the 20s by either the Blazers, Nets, Lakers. Jazz or Magic who all have multiple 1st round picks. I also don't think Collins should be ahead of Markkanen.
I think Collins will be a slightly better pro b/c of a bigger low post presence.
The Big Board is subjective and dependent on team needs. That being said, I like Ford's list, with a couple changes (bolded) to resemble what I think would be the Celtics big board.
Fultz
JacksonBall
Tatum
Fox
Dennis Smith JRMonkIsaac
Zach Collins
Markkanen
Frank Ntikilina
Jared Allen
Frank JacksonBam AdebayoHarry Giles- borderline 1st rounderFortunately, we're not going to have to worry ourselves with the guys past Tatum.