I think Jeb or Cruz would loose. Jeb was seen as similar to his brother and Cruz has little appeal outside of solidly Republican states. Rubio or Kasich could win.
Jeb! would have been seen by a lot of the public the same way as Hillary: scion of a much maligned political dynasty. A Bernie Sanders vs Jeb! Bush map would be interesting to see. Sanders might actually make gains in KY and WV. Not enough to win them, but maybe get close to within single digits.
The way Jeb campaigned, he might as well have pledged to make Liz Cheney his running mate. Jeb literally said, “I would have gone into Iraq.”