Wolf: who said at the expense of something else?
It has to be at the expense of something else… unless you’re positing two candidates that are otherwise completely equal.
Considering the fact that I consider “personal preference” to be a factor that outweighs z’chus avos (as in “I would rather marry him/her”), I find it hard to consider a case where any potential “z’chus avos” would even come into consideration.
The Wolf