I can't be 100% certain, but they might be using the standard weight Guan Dao (Kwan Dao), but it's also possible he's using the Wushu version that's significantly lighter. The heavier (Wuzuquan or Gojo forms) Guan Dao can weigh between 25 and (!)50kg, when consisting of metal handle and counterweight.
You'll see how they have moves that pause at the end when a significant change of direction is called for, but there is also quite a bit of follow-through from one move to another. These are all competition demonstrations by some of the best in the world, which should be a good example of how heroes in the game should perform at a minimum.
If your game behaves like this, then it's perfectly fine!
EDIT: After a re-watch of the video, I notice they are all using the lighter version of the weapon, with wooden handle and the flexible blade, I don't know if you'll find a video using the heavier as they are not as impressive to the uninformed.
EDIT 2: After some more searching I found more relevant videos
You'll notice in both videos, the blade does NOT wobble, and the performers are not stick thin people, but a bit more on the heavy side, as is required to handle the heavier blades, I suspect these are about 25kg (50lbs) weight.