You're wrong.
2.18 (5) is only about the financial requirement. It is not the full set of requirements.
The child must live with the alien, be unmarried and not be over the age of 20. As per 2.18.
As for the financial requirements, see 2.18(5) which refers to those and only those.
If you think 2.18(5) is the full list of requirements it would mean that you think the child can live anywhere, be any age and be married with their own family. Say, be 40 years old living in another province with their spouse and 3 children.