Three reasons why it is very difficult to compare Knight and Harvey at the NCAA level: they play different positions; the latter played her whole career with Olympic experience, while only the second half of Knight's career was as an Olympian; and the game has changed a lot in terms of training/teaching over the 15 years that separated the start of their college years. I'll just say that as frosh, both ended the NCAAs for UM with OT goals, so I have them filed away under unhappy memories.
I agree that Harvey is likely to win the Kaz. My guess is that the voters look at the numbers like Badger fans do, if they bother to look at them at all. They won't figure out how much the Gopher offense fell off a cliff when Murphy left (they went from averaging over 5.5 goals per game to fewer than 2; yes, they lost other players, but not of the caliber that UW lost), while UW was still able to find the net more often than not. Similarly, you can look at the boatload of penalties called on Murphy, but if you don't factor in all of the penalties she draws, you're missing much of the picture.
Coaches want their teams to be difficult to play against. Murphy makes that true single-handedly. She also takes a beating and keeps coming back for more. Yes, there are some hooks and holds that may be imaginary to an extent. However, there are also opponents who just line her up and drill her all weekend. During her career, there have been more ill-advised plays on her part than I care to remember, but this year, much more of it has been in the tit-for-tat side of the ledger. We might want her to be a child of Lady Byng, but when she looks in the mirror, she sees a missing Tkachuk sister.
Harvey will win, but it's not because other players aren't deserving of recognition. (Although, it is fun to imagine Timothy A spontaneously combusting if Ève Gascon won

.)
A good offseason topic: best player(s) from your program to NOT win the Kazmaier.