I agree that if Suggs or Green are the pick, one of Sexland will be either moved to the bench or traded. I actually think Suggs is a great fit next to Sexton, and Green a good enough fit next to Garland.
But I don't agree that Sexland was a mistake. Garland was clearly the best talent available at 5 in 2019. In their two years together, neither of Sexland has hindered the other's development. Garland's value is probably higher or as high as any other player selected after him. Taking BPA in those drafts have set us up nicely for this draft IMO, that we can take Green OR Suggs and feel great about getting good value back for one of Sexland to construct a team that makes more sense.
I don't know, I just think talent accumulation is the most important thing when starting a rebuild.