modern times, his voluminous coverage of diverse human institutions demands respectful scrutiny. Yet, as every other controversial thinker that has lived before or after him, his works are seldom free of idiosyncrasy, eccentricity, or sometimes even outrageous rubbish. the link below is an article discussing Nietzsche's "great" advice on marriage. you can read it and decide for yourself how much truth, or equally, fallacy, is in there.