"And the couple should have a BIG Marriage with loads of functions and relatives." Couple should be of same religion, they should speak same language, they should be of the same social level etc..
When they fill the PR application they should overload the Immigration Officers with loads of their pictures, greeting cards, emails, phone records, they should also write letter to the IO explaining about their relationship (like how did u meet and how the relationship grow). Send as many things as possible so that IO has no reason to reject your application or call u for an interview.