As for "draft experts" every year at this time they have a player or two ranked as a first rounder that will end up being a 6 7 or undrafted FA, so that's hardly Gospel.
They have those types of players, but those mocks are usually before the season starts. Kiper and McShay both updated their big boards. Both have them going in top 20. McShay has Mingo going #7 and Montgomery going #22. Kiper has Mingo going #13 and Montgomery going #14.
I guess Kiper/McShay didnt get the memo about Mingo's lack of production
Or maybe sometimes players get drafted based on potential