I want to suggest to make the stun system more "realistic" and fun, by removing stun for low damage attacks completely and adding damage based stun for harder attacks, if possible at all.
Example:
0 - 15 HP damage = 0,00 sec stun
15 - 20 HP damage = 0,10 sec stun
20 - 25 HP damage = 0,12 sec stun
...
could be %wise depending on player-hp aswell
Realism point of view
When you fight for your life, your body is flooded with drugs, adrenaline and so on, basicly you wont feel much pain until the situation calms down. Everyone who has been in a brawl, a car accident or whatever knows what I mean. A knight/soldier fighting for his life who gets scratched by an arrow or a swing, will for sure not stop his swing or blocking attempt, because it would mean his death. A hard hit like a sword penetrating his armor will stop him for sure.
Gaming/fun point of view
The stun system is simply annoying in this game:
In groupfights you are often like perma-stunned - feels like beeing stoned to death..
When you happen to end up in one of those rare 1on1 situations you often get shot -> stun -> dead..
Survivability has been decreased a lot in last 18 months, this would be small step back to hero-mode!