Heteronuclear Molecular Orbital Diagram

[Madeline Fox 2B]

If both Atom A and Atom B are Z>8, but they are heteronuclear, which diagram do you use? In the course reader, it says that "Heteronuclear with Z mixed use the z<8 diagram". However, I am not sure if he means you use that diagram only if one atom >8 and one is <8, or if you always use that diagram for heteronuclear molecular orbitals.

[Jane Sin 3A]

Heteronuclear problems will always follow z<8