Ok - but biology is complex and evaluating what is plausible can be subjective. A study can cut throw the noise if done properly. I agree a hypothetical mechanisms of action must also be plausible, but that is something that further studies canhelp refine.
For example, what if statins do lower CVD risk in a RCT, but due to some different mechanism than their purported LDL lowering? maybe they act as mild blood thinners.
How would you recommend a properly skeptical patient with a family history of CVD evaluate the various preventative measures they could take?