I rank prospects based on the gun to your head mentality. In a vacuum I like Kulak a lot but his waiver status diminishes his value a bit in my eyes.
I still really like Mangiapane upside. If everything works out I think he could be like a Zuccarello.
I have Mangi, then Kulak, followed by Foo.
Kulak's in a werid spot, where we don't evaluate him like other prospects. The guy's a decent bottom pairing Dman already in the NHL (not amazing, but also not Engelland/Bartkowski tire fire); but we completely forget that every time he went down to the AHL this past season, he was playing 25+ minutes a night in an all-purpose role (so kind of a 1D role).
On one hand, you have exactly what you'd want in your older prospects, he's playing at the highest level outside the NHL; but you also have this thing where he was used as a #7 most of the year... and in total played 43 games because of it.
I still think some people are sleeping on this kid; I do think he's an NHL'er... at what level though? Completely uncertain.