In a situation like this, I'd think it's hard to come to any conclusion about how this might end. Because, as it is the way humans have come to think, all things come to an end- good things included.
Although there may be a good match, bad things can still ensue. If there's too much tension and not enough compatability to counter-balance it, the marriage may just fall apart.
However, out of every bad thing, comes a little good as well... So, perhaps the marriage WILL thrive? It all depends on what happens and when. Maybe something will happen and they'll suddenly be reminded about how much they love each other.
Like I said, NO ONE can predict the future and it's outcomes.
I hope things turn out for the best anyways! Good Luck, my friend!
+~*Yosei*~+