body ground module of wiring fundamentals

What if the engine mounts are both made of conductive materials? in this module it is said that it is very important that there must be only one connection from the engine to the body... do 2 engine mounts count as 2 connections?

I think it would be better to say "it is important to have at least one good ground from the engine to the body". One particular problem to be looking out for is that metal connections to anodized aluminum are not very conductive. I have made anodized aluminum brackets for alternators, and often have to provide a separate ground to the engine as the mount has too much resistance.