It's not that they are better off or not. It's that if you are White with an even half decent cash flow, you have a significant advantage in securing a non-White wife. White is a beautiful skin color and those outside of the race find it attractive and exotic. So it isn't too tough for White guys to be passport bros, there is a massive demand for White men outside of the White race, far higher than within the White race.
As for miscegnation, that does not exist if one marries within the Church, and that goes double for the Orthodox Church. Does not matter what race she is, marriage is a holy sacrament and blessed by God. There will not be miscegenation through Orthodox marriages.
Those are the WNs I can sorta understand, but again, it makes no sense for a WN to be upset about White men dating out of the race when there is a supply issue. White Nationalists are basically asking White men to go celibate until their White unicorn comes along, which is just laughable.
It's already next to impossible to get men to go celibate for God, can you imagine asking them to wait 5-15 years for the mythical good White girl? Just ridiculous.
But this misses the point. It doesn't matter if Vance dates outside of his race because there is a shortage of eligible White women. That's WHY the manosphere exists, a massive glut of single White men who cannot find a suitable WF to marry.
So it doesn't matter if Vance marries out, if anything, he's doing other White men a favor because there is less competition for White women now.
As for his wife being pagan, it's actually not an issue for dozens of reasons, chief among them is that the Church has been dealing with this for thousands of years. As long as they marry in the Church and baptize their kids, the spouse is extra. Since both of these things have happened, then it follows she's a good wife who just hasn't made the full conversion yet.