”O Coen brothers, where art thou?” you may ask during the bumpy first half of the Blood Simple masterminds’ broad-as-a-barn-door retake on Homer’s Odyssey. Transmogrified into a picaresque tale of three Depression-era chain-gang escapees (Clooney, Turturro, and Tim Blake Nelson), the script initially seems like a string of toothless Southern caricatures. But fine turns by Raising Arizona alums Holly Hunter and John Goodman — and T-Bone Burnett’s old-timey soundtrack — eventually vivify the movie.