Sylvan Safekeeper could be the difference between keeping or losing the best card on your side of the board - and in those instances, a lost land doesn't seem quite so bad
Usually we look to a new set to shake up the current Standard format, but we currently have a strategy that is so incredibly dominant that many people believe the new cards wont be able to shine
Not to mention, Unearth is not legal in Standard or Pioneer, giving Helping Hand additional opportunities to shine
Devour Intellect, on the other hand, is actively poor on Turn 1
but they also took advantage of kids (the younger the kid, the more they'd take advantage) by offering them even less than one would normally get for a trade in and charging more for whatever they were selling
I don't think there are archetypes in this set but I maybe wrong on this one