I think if two people meet and are incompatable they should discover this almost immediately.There are many many people who love each other and row and argue ,but can't live without each other.My best friend and his wife are a prime example.They are not happy unless they are rowing,but they are so dedicated to each other.
If there is a conflict but no love,then there's no hope,regardless.If there's love and conflict,then it's does not mean it can't,won't work.True love knows no rules.