As someone who is currently at a similar crossroads in his life-- at this exact moment-- I think this is really sturdy advice. I've probably been so active commenting on this thread because it's such a fresh area of testing for me.
Go with whatever seems right based on factors that play into marriage: attractiveness, personality, whatever. You have no way of knowing if God wants you to marry person 1 or person 2, as frustrating as that might be. Marry the person you're more attracted to, the one you think will be the better mother to your kids, the one who makes you feel the best.
When my first marriage ended tragically in divorce and I ventured out solo for the first time in 17 years, I desperately wanted to feel "safe" again with someone eventually on this ragged-ass road of life. After close to 2 years of singleness, I think I've found someone who fits that bill. But I also recognize in myself this urge to want be "certain" and have tried repeatedly to find a concrete answer that will translate into me never having to endure the pain I went through, again. The bottom line: I've done almost everything to find 100% insurance against experiencing that agony a second time-- including listening for a still, small voice.
But the grown-up fact is: 100% certainties don't really exist as far as people and relationships are concerned. Deep down I know this. In my well-meaning rebellion, I have tried very subtle, nuanced ways to secure that certainty via prayer, meditation, questioning, verbal affirmations, counsel from friends, etc... But at some point, I had to make the decision that I could only gather all the objective data I could know to make an informed decision, combine that with what my heart feels and then... frankly, just go for it, live life and be HAPPY. It is terrifying and sometimes stressful thinking of all that could go awry in my future... and I secretly wish God would say something to me directly, to help. But he hasn't. Let's face it-- he probably won't. And I understand.
But this I know: no matter what happens to me, I am loved and somehow, beyond all conception, accepted by God, unconditionally. I am promised that. Apart from this I am also promised struggles and joy on my journey. It's enough.