Harry and Ginny are real soul mates. They’re both very strong and very passionate. That’s their connection, and they’re remarkable together. Ron and Hermione, however, are drawn to each other because they balance each other out. Hermione’s got the sensitivity and maturity that’s been left out of Ron, and Ron loosens up Hermione a bit, gets her to have some fun. They love each other and they bicker a bit, but they enjoy bickering, so we shouldn’t worry about it.
J.K. Rowling (link)
I have been saying that Ron and Hermione balance each other out for years and years and years. <3