If I have a key to a portal with 8 resonators, and I approach a portal with only 7 resonators, I cannot link the portals - I have to add a resonator first.
But what about the opposite situation? If I have a key to a portal with only 7 resonators, and I approach a portal with 8 resonators, can I create a link between them?
(If not, there may be some point to destroying only one resonator of a strong enemy portal - to prevent links from being created.)