I agree that unit and killing speed are slightly too fast for my liking. I had to chase a routing unit of exhausted Hastati all over the field before I trampled the last one during the Trebia battle. My Sacred Band Cavalry had problems keeping up with them and they were still fresh! :) Of course, watching my cavalry trample them all was highly enjoyable, but slowing down the unit's speed would certainly be prudent, I feel. As for killing speed....Well, high valour versus low valour, what can you expect? I withhold my judgement about this until I've played the full game. :)