With Silayev, the question is almost more "what kind of offence might eventually be there?", because he doesn't really have an offensive game right now.
With guys like Yakemchuk, Parekh or Dickinson, we kind of can see what they do and it's a matter of projecting their skillsets and styles to the NHL. With Silayev, it's more theoretical - what kind of offence might emerge from a guy with his size, mobility and functional puck skills? Chara, to use a best case example, wasn't producing offence as a prospect, but he was such a unicorn athletically that he turned a fairly modest offensive skillset into 40-50 points and 10-20 goals a season.