Most experts would hesitate in describing the differences between clones and incarnations. A clone would possess just a small part of the true body's power. As for how much it was? It depended upon how profound was one's cultivation method. One's true body wouldn't immediately learn of what the clones had gone through, and it was only in specific circumstances that it was possible to learn of what they had gone through.
An incarnation's status was vastly higher than a clone, and it didn't just possess great fighting prowess, its mind was also linked with its owner. In other words, regardless of how many incarnations one had, they still all had the same soul and mind.
This was why if Jiang Chen refined the clone, the Sacred Lord wouldn't probably learn about it. The clone was just formed by energy, and such energy came from a Martial Saint was on a par with an Immortal Elixir.