I think it might also be possible that during the siege at Weathertop, the WK operated by Sauron's "wisdom," driving his men (such as they are) from behind rather than leading the fray, and he simply never got to the front before the confrontation ended, or truly entered into direct combat with Gandalf. Perhaps he considered himself a much better tactician/strategist, and felt the strength of the others would be adequate to the situation while he directed their efforts.
Well, it's a thought.
