From what I have seen and understand from the issue, the problem is in the physics.
They are making everything respond physically the way it should in real life. this can be seen in the video update about combat.
Its a complex system, and pole arms are rather large and they have many variables when it comes to physical reaction.
All this on top of the Mocap issues mentioned above by @ProkyBrambora I think its easy to understand why its a complex challenge.
I am confident in the WH team and trust that they will try their absolute hardest to make it a possibility, but the reality is that it may not happen at least not in time for Act 1.