Not how that works. It would be 4672 * 2.08 = 9718, NOT 4672 * 1.78 * 1.3
So like you said, guy isn't wearing armor, with 0 expertise, while you have wz expertise buff AND something like inspiration just to break 10k. So it is either a setup or a glitch.
If you wanna try to get the high hit you wanna get your max psec
That will give you +10 % power
so if the guy is hitting 9718 whitout inspiration and whitout the 10% power how much wuold it be max ?