You'd "think" about it??
Yup, I'd think about it. You have to consider that these two wingers - Knight and Rattie have different play styles and physical traits. Knight is bigger and more physical, a more punishing straight driving play style. Rattie has to rely on finesse and speed. Knight is 5'11 and 96kg, Rattie is 6' and 76kg. Big difference there in physicality.
Also although Rattie had sparkling point totals in the WHL you have to consider that the competition is different. Knight was putting up his numbers in the OHL.
Knight
http://www.hockeydb.com/ihdb/stats/pdisplay.php?pid=116045
Rattie
http://www.hockeydb.com/ihdb/stats/pdisplay.php?pid=118248
You also have to consider both were taken with the exact same pick position but in different drafts, round 2 pick 32. So talent-wise their projection must have been similar at the time of the pick.
Of course right now, I'd certainly consider Rattie to have the edge. But it's not at the point where I would be able to say Knight wouldn't be able to catch up next year or something like that. I did say Knight+ would be needed if a trade were to happen, but it would depend on what the plus would be.
Just look at Matt Fraser for instance. His numbers aren't far off from Rattie and he has fewer games played this season.
http://www.hockeydb.com/ihdb/stats/pdisplay.php?pid=81250
And as I said for Spooner. He's just starting to come into his own but he's already a PPG player at the AHL level. I think he just needs to get a little stronger and mature a bit, then he will be ready for the NHL level. He has a tantalizing blend of speed and skill and we shouldn't give him away too soon. Particularly when his value will only increase as he gets better.