I think it is a stupid discussion about the shield form of the champion.
It is a unique skill, and if you remove it, or nerf it to the ground, especially what Madoxx have said, the champion will loose his unique style.
If your goal is to make all tank classes the same, or more of the same, pleaso do so, but my understanding of the multi class system is, that you have to keep the differences of the classes.
I don't think, that the Ch/K is overpowerd. He is very very tanky, yes, and has alot stuns - pretty strong tank class.
But he is lacking: 1. DMG-Reduction for the raid (like K/M), 2. Supporting with Raid-Buffs (like K/D, K/P)
I like its tankyness, but tbh if I had full tank gear, i would play Knight/Mage.
If you demand a nerf of Ch/k. Don't nerf generall Champion skills, that effect all Champ-Combos, but its elite skills