I know Francoeur has a great arm, since I have seen it many times while he was with the Braves. But I can tell you that each one of those guys, especially Hamilton, has better range. And Hamilton has a great arm as well. His defense is what will put Hamilton over the top WHEN he wins AL MVP this season, not if. Idk how much you see of Hamilton, but if you want to see a little of what he can do, then go here...
http://mlb.mlb.com/mlb/gameday/index.jsp?gid=2010_08_13_bosmlb_texmlb_1&mode=wrap
and check out all of his highlights just from that one game. Obviously focusing on the defensive plays since that is what we are discussing. Four hits, two great catches in center field, and scoring from 2nd on an infield hit. The only outfielder I would put Francoeur in over is David Murphy. That's not to say he is bad defensively, but I'll take Francouer's arm. Unfortunately I'd take Murphy's bat, but you can't have both.