Marriage in Middle-earth II (unhappy)

[akhtene]

Sorry if it's not the right thread to post it, but...

Manardariel wrote in another thread *Happy Marriages* that couples had to part and wait before they could get married, and it worked well for them. But it doesn't seem to turn out so well, if husband and wife have to part. It's a disaster not only for them, but for many and many around.
Gorlim parts with Eilinel: she is killed, he gets caught and tricked into betraying Barahir and his men.
Aredhel leaves Eol: both are killed, and their son causes the fall of Gondolin (to where he probably wouldn't have got, if the parents stayed together)
Morwen, left behind by Hurin, can't protect her children, and...well, you know the story, including the gift of Nauglamnir to Thingol by despared Hurin.
On the other hand, Earendil makes it to Valinor after reuniting with Elwing, the Silmaril she carries being the pass.
And Lutien returns Beren from death by bravely following him to Mandos.

Is this supposed to stress that man and wife must be one, and their separetion can only do a lot of wrong?