[Zigûr]

I think the "thing of surpassing potency" description of the Ring is not mutually exclusive with the common "built-in vulnerability" theory which argues that Sauron's contribution to the Ring-lore which made the Three involved making them in a way that would be vulnerable.

It may have worked like this:
1. The built-in vulnerability aspect allowed the One to influence or control the Three and their bearers.
2. The "surpassing potency" of the One allowed the One to control the works wrought with the Three.

This, however, does not seem consistent with the notion that Sauron would not have needed the One to overthrow the defences of Lórien had he come there in person.