ex-would-have-been husband

Are the following expressions correct, and are both equivalent? Please let me know. Thanks

1: He is your ex-would-have-been husband (“He” could have been her husband but the circustances etc. didn’t permit it).

2: He is you ex-could-have-been husband.

To me, “would-have-been husband” sounds more like there was an actual plan, or a genuine possibility, that they would marry, but then the plans were scuppered. “could-have-been” sounds more hypothetical.

I’m not very clear what the prefix “ex-” is adding. It seems possibly redundant to me, because “would-have-been” and “could-have-been” already give the necessary past sense.

Thank you, Dozy.