OK, that's not a problem. The totality of circumstances would also include your age, his age, and his earning capability, based on his past employment experience, and the country he's coming from. Trying to help you understand here, but the reality is, what you need to understand is that a well qualified joint sponsor is required.
What is the exact wording the goes with the mention of a joint sponsor? Leave out any names. Knowing that may or may not help.