Whole sign or House cusps (4th, 10th) when evaluating capacity for relationships?

Hi folks, just a quick basic question about what you look at when evaluating a man or woman's capacity for relationships. So for men the Sun and the 10th are very important, while for women - the Moon and the 4th. The question is - do we look at the 4th or 10th sign from Lagna, or the specific placement of the 4th or 10th cusps? And does this apply to both the Rasi and the other vargas? In the course the cusps are not even shown in the class charts, but I'm mindful of the fact that it's an older course, so I thought it best to consult with you.  

Thank you so much in advance. Purely based on some charts of friends I've been looking at, the cusps seem to be very important, perhaps I should be mindful of both 🧐