Hey "marriage expert".
I admit to NOT reviewing the article you link to (supposedly documenting that co-habitating, at best, does no good; and at worst helps contribute to broken relationships.
But I KNOW this is dead wrong. I'm not saying that in ALL cases or even MOST cases, it's a good idea to co-habitate first. No way "one size fits all". Certainly people with beliefs about morality that go against living together out of official wedlock - those people would naturally have a far higher rate of their co-habitating resulted later in failure. Unfortunately, this doesn't tell us much; and certainly can't be any guide for other couples who are thinking about whether to co-habitate first.
My basic point: I've been in TWO GREAT relationships (the first lasted 8 years, the first six of it - sensational); the second 31+ years - we're still honeymooning; we love each other more than at the beginning - and we started off crazy for each other.
In both those cases, we lived together BEFORE getting officially married. I KNOW that co-habitational period was the right decision - we found out, and quite quickly, that we had a good shot at lasting because we had already lived together; experiences some of the best and worst in each other - gotten an idea about how good (or bad) we might be in working out compromises.
I've also marriage counseled 50 some years worth of couples. I testify here (for what it's worth - it is, afterall, for everyone else, just my word (just as what I said about my two wonderful relations were essentially hear-say)) ... I testify here that well over 1/4th of those couples had co-habitated - and that those who had co-habitated averaged (over 100s and 100s of couples) about the same degree of success as the couples that didn't co-habitate first. I must add one other "extenuating" circumstance. The YOUNGER the couple, the more the benefitted from co-habitating first; and the less they were successful if they did not? Why?
Because the younger the people involved, the more, inevitably, they are going to change; even just grow up more - and the frequency with which they still match up well thru and after many big changes - that frequency argues strongly FOR co-habitation first. Then, if it doesn't work out; you have less legal ramifications (and less "in-laws" budding in, taking sides, criticizing, etc). If it does work, "no harm, no foul". The test period obviously worked.
There is such a thing as "probation" and testing periods. These are just as usefull, just as powerfully useful for love-relationships as they are for pretty much every other circumstance in which such periods are involved.