An Arkansas native himself, Clark Duke had always wanted to tell a story surrounding the Dixie Mafia from the region. His big reason was, as hinted towards earlier, his own grandfather was, as he puts it, a “tertiary figure” in the criminal environment working out of his home state. So with the novel of Arkansas giving him the perfect character in Frog, all that was needed was the perfect actor to flesh this figure out in living, breathing color.
Article source: https://www.cinemablend.com/news/2496043/why-vince-vaughn-was-the-perfect-villain-for-clark-dukes-new-film-arkansas