I think any relationship between two people who are very different from each other can be unhealthy. That’s why communication and trust are such vital components to a relationship’s success, and that’s why, when it comes to Xena, I prefer Joxer/Gabrielle over Xena/Gabrielle. Xena is just too much of a “hit first, ask questions later” sort, and frankly, judging by how she acts in some episodes, I’m inclined to believe she actually enjoys killing to some extent. Joxer may be deluded about how much of a warrior he is – which I chalk up to how, and by whom, he was raised – but deep down he’s gentle, and I think he’s more the type to actually talk to Gabrielle and trust Gabrielle, rather than condescendingly treat her like a child who can't make her own decisions.
Xena/Gabrielle have their moments (and those moments can be beautiful), but all in all, I think Joxer's gentle and lively nature is more Gabrielle's type.