I love your posts and certainly respect your opinion. However, I don't think either Anthony Newley, Kenneth Nelson, or Sammy Davis (for that matter) played Littlechap as a nebbish. Littlechap is brash, aggressive, and certainly working class. He seduces, then reluctantly marries the boss's daughter, enters politics, and is an unfaithful husband (multiple times). None of that behavior strikes me as that of a nebbish. Perhaps Joel Grey portrayed him that way, but I don't think it's necessarily required.
Jackman has working class roots and knows the territory. He certainly could do the part justice. I assume his name was mentioned a few years ago for a possible revival because he would definitely sell tickets.
Whether we like it or not, Broadway (and off-Broadway at times) theatre is a business. I'm sure that's why Jonathan Groff was originally cast as Seymour in the recent, very expensive off-Broadway revival of Little Shop. Gideon Glick was certainly more the nebbish type, but did his presence ever sell out the house like Groff's did?