How would manual blocking function? You hold a button and have to manually aim your blocks (not sure how you'd do this accurately with a mouse cursor)? If you're suggesting to press a button in order to block how the character already does then I don't see much point since it's a bit redundant.
I think blocking already is pretty active given that you need to control your positioning, momentum and balance to block properly. You also have the option of doing an active defense by bashing your opponents weapon out of the way with your own attack, which I find pretty varied.
If you have ever fought or sparred before, blocking is pretty much an automatic instinct, how fast you are and how strong your blocks are depend in training. I do think they need to put more actions for combat in but I think blocking is more realistic the way it is
How about expanding the current block instead?
Turning your character towards the direction of the swing would strengthen the block and require good timing for the best results.
Simply looking in the direction the swing is coming from would be a bit weaker than it is currently.
This would make feints more effective and add more skill to blocking.
I'm aware this probably already works to some degree, but it's not very noticeable and overall I feel blocking could be made more reliable for skilled players and less so for bad ones.
I can see the appeal of a manual block, there are times when an opponent will throw an over head attack and I'll just do nothing expecting my character to block the incoming shot, only to have him ignore it and let it smash straight into his face T.T but at the same time most games I've seen with manual block don't have as interesting game play. People tend to spend years of their lives learning to block perfectly so that they can ably defend any possible string of attacks and feints. This system with a manual block would be extremely easy to defend. the movement are relatively slow in comparison with other games in the genre and I'm OK with that because they have weight and physics instead of just animations. The blocking not being perfect is actually pretty good for the overall design of the combat as you really should be using your measure as your first defense and your weapon as your second as weapon blocking in reality is none too reliable either XD.