If you speed up swings, you won't be able to block without a shield because a split second is required to determine which direction a swing is coming from so the right block direction can be determined and executed.
Some kind of limited sprint capability would feel good. I don't know how much I'll appreciate my opponents sprinting away from me when they are running, but overall it would make mobility more dynamic.
I don't see a problem with horseback archery. It is already conceptually strong and the penalties to accuracy are both realistic and necessary for balance. Maybe the accuracy when standing still on horseback could be a little tighter, but it should never be as good as standing still on the ground.
Lethality in combat seems about right to me on the Realistic settings. You can one hit kill unarmoured enemies with a heavy weapon strike to the head (including high tier ranged weapons, or any javelin lol). Most other situations should take more than one hit.
I also feel that blocking with two handed weapons could do with a bit of revising. Like for example swinging from right to left whilst holding block could make you swing your sword/axe whatever from right to left in a defensive manner to block swings from that side. A change like that would make the combat more immersive and also allow players to react more quickly to attacks, which in turn would also facilitate a small increase in swing speeds
To expand on using bows on horseback, i think it’d be awesome if they made timing your shots more important and increased the skill gap, allowing more skilled players a greater degree of accuracy whilst increasing the penalty for mistiming shots.
Mongol and Hun horse archers were taught to loose their arrows when all four hooves of their horse were off the ground and the horse was at the peak of its arc [i’m not an equestrian and don’t know the right words to use here lol but if you’re curious it’s worth googling] because that’s the moment when they’re the most stable, allowing them to be as accurate as they could be.
I would love to see a system like that in-game.
I agree that shooting whilst moving on horseback shouldn’t be as accurate as if you were stand still with your feet on the ground but atm the combat feels too level dependent imo which stifles the gameplay and frankly in the early game combat is a grind imo