In step 9, the attacker is removed from the board if they fail? Surely that doesn't include archers. :)

What if the attacker is within a terrain feature? If two warriors are on a hill together, it seems like neither should have an advantage.

How do you avoid stalemate problems? For example, if it's down to a knight versus two archers, the knight will not want to close with the archers, and the archers will be unable to close with the knight.