Pogrebnyak scored 6 in 12 for Fulham. It's a very small sample size but puts the likes of Bryan Ruiz and Dembele to shame, who are also considered very highly. Pogrebnyak is a goalscorer, and has been throughout his entire career. Even during his 'drought' at Stuttgart he had a decent record, so history says he will come good, sadly.
I think Guthrie is a premiership player too, maybe not top half - but give him some credit. He's racked up over 100 games with the likes of Bolton and Newcastle in this league so he must be fairly decent, and whilst I don't think he's amazing I don't think he's that bad either.