Do SFR = more equity where MFR = more cash flow?

[Scott K.]

In the BRRRR podcast, episode 327, David Greene made a comment (1:08:30ish) suggesting his single-family homes tend to add equity for him and his multi-family homes contribute more cashflow. He suggested the two asset classes work with one another in a complementary fashion.

Can someone explain why this is true (particularly why single-family properties tend to add more equity). I'd be especially curious to see any example math behind this if it exists somewhere.

Video: https://www.youtube.com/watch?v=FBci62dfqaY