Here is a product data sheet on the Z-Rod oil:
LINK
This data sheet shows the zinc and phosphorus levels in the Z-Rod oil, as well as several other of the Amsoil oils.
If Z and Ph are your goal for anti-wear, then use the Dominator.
Z-Rod has higher levels of rust and corrosion inhibitor additives, and may be a better choice for those people who store their cars, or use them infrequently.