I live where no hickory grows and would take all I can get.
The "better" woods are usually more dense, but differences are subtle. It may let you get away with a bit more.
F'rinstance, I recently made two elm flatbows from two small trees growing near each other. One is "dream" elm; clean, hard white elm at about .66 SG. The other is a better than average stave of the elm I usually find around here, more heart wood and lighter. About the same diameter, etc.
The bows are 68 and 68.5" n2n. Same limb profile, reflexed and heat treated on the same form. The "good" elm has about 5/8" longer handle, sllightly longer stiffer tip secfion, and pulls 54 lbs. The other feels lighter in the hand, has slightly shorter fades and pulls 52 lb. The "good" elm kept maybe 3/4" more reflex, but the "poor" elm does have a small knot in the lower midlimb that I had to leave stiffer, so.........?
Anyway good luck!