Mate, Kone was born in 1983. He is older than Naismith, who was born in 1986. What about that is unconvincing?
And I never said Naismith was prolific - in isolation that would be a meaningless statement. I said that he was more proven as a prem goalscorer than Kone, which is a simple comparison of their respective scoring records. Naismith has scored more goals, and made more assists, for us and Norwich than Kone has for Wigan and us.
If Naismith is average (which I wouldn't necessarily disagree) then, by comparison, Kone is below average at best. It's also a fair assumption that Naismith, as the younger man, will add more goals and assists to his tally form this point than Kone will.
Naismith - 19 goals in 104 Prem apps
Kone - 17 goals in 73 Prem apps
It would appear Kone averages better