Stoke v Watford - What am I missing?

Big confused by this one. Expected Stoke to be shorter than 4/5 and I see they're actually on the drift. Stoke's form might seem ropey of late but they've been operating against the very best in the division - away. And their home form is a bit deceptive too, unlucky not to collect 3 points v Leicester last time and played most of game v Saints with 10 men after Arnoutovic saw red early on. Stoke's record v bottom half teams is pretty solid, I think they're in a bit of a false position at the moment - could easily be 4 or 5 places higher in the table, Arnoutovic returns from suspension tonight and lets face it, Stoke never the nicest place to visit, esp on a cold January night. Watford on the other hand in a tailspin, looked clueless v Spurs on Sunday and have been woeful on the road of late. Scored a sloppy injury time goal at the weekend but before that had only a pen to show for previous 3 games and struggling badly for goals. Stoke gave Chelsea a right good game on Saturday while Watford never tried a leg v Spurs and Stoke have already beaten Watford at their place just 5 weeks ago so any reason I shouldn't steam in to Stoke at the prices? 11/8 about them -1 looks a monster price and strongly tempted by the 9/2 -2 if I'm honest.