I'm not crazy about either Dukes or Werth, but you certainly own the right player.
1B and OF are absolutely a mess for the Nationals right now. A look at Washington's depth chart
, shows that Dukes will have plenty of competition for playing time. Plus, his contact rates don't suggest that he's going to be able to improve his BA much.
Werth certainly has the ability to repeat his numbers from last year. He was only caught once in 21 SB attempts last year for a reason (he knows how to steal a base) and an ISO of .225 is fairly impressive. As a LD hitter, Werth's BABIP should also remain fairly high and, as such, his BA should remain respectable with a slight chance at improving this year.
Both of these guys come with risk since neither is very proven at the major league level. But, at this point, I'd much rather own Werth.