I realize this can’t work all the time, but, here’s a wild idea…
Most frum families have 4 or more (often MANY more) kids.
Why not at least try, when the ages work out, of course, for brothers and sisters to make shidduchim for their siblings with their friends! They know the true matzav of their friends, i.e. what kind of people they are, and of course, they also know what their siblings are really like (and what they really want) as well.
I realize the ages may not always work out, and the personalities may not always work out, but this me’halaich should be the first method tried. This way everybody knows the truth about they’re getting, and parents could save $$$ on shadchanus.