Well, to me a soulmate is someone, who "completes" you.
Completion as in compliments your caracteristics. Filling and correcting the flaws in your personality with their own personality so that the two personalities (souls) fit like a puzzle piece.
Those two van easily fall in love since they compliment each other and fill in the holes that they have in each others feelings.
That's a more philozophical explanation from me lol...but yes...i do believe in soulmates as ones who may not be destined to be together, but are DEFFINETLY great together as a couple since some of us are destined to stick with people who beat us up and treat us like trash but, we love them for it...