Regina wanted a huntsman to kill Snow white for her… Why? She has dozens, maybe hundreds of Black Knights who I assume she has ripped the hearts out of and have full control over.
Well, they answer this in 107, though I admit the whole ‘she has hearts” thing is a loose thread” I don’t know why Regina didn’t order a black knight other than PLOT but this is the in show answer
Evil Queen: The kingdom’s still loyal to her. They would turn on me. They don’t know the wretchedness inside her as I do. They don’t know what she did to me. We must be delicate in this next phase. Her demise must be handled with care.
(She gets up and walks towards the exit.)
Mirror: Perhaps, one of your knights, Your Majesty?
Evil Queen: No. I need someone adept at murder. Bereft of mercy.
Mirror: Someone with no heart.
Evil Queen: Now you understand.
Mirror: Well, in that case, you need a huntsman.