This comparison of power in the two paths of the golden core is the best that these weaker beings at the third mortal coil could tell by looking at the three of them.
And this was only if these foundation establishment cultivators were informed about the state of existence of the fourth mortal coil.
But aside from this information, there was nothing else that could be seen. This was because the three of them looked alike from afar.
To be more accurate, it was that the foundation establishment cultivators couldn't see the facial features of the three of them. So the three of them just look like bright golden people. In fact, the weaker ones looking at them might be blinded by the glow of their existence.
But one of the people of the Purple Flower sect at the peak of the third mortal coil wanted to see what the golden core cultivator of the Blood Skull sect looked like and had also trained a visual technique to help him discern Arthur's features.