No, no, no....not perceived as a fight partner. Good question.
The primary reasons I believe this product to be better suited to our needs as hunters is the flexibility offered in the circuitry. Two independent lighting systems affords redundancy (failure rate is pretty minimal with two systems) and the ability to regulate the light beam to a very low setting, thus maximizing battery life (150 hours on a low setting). That's a big deal when you're counting ounces in your pack in that you don't have to hump spares.
Head mounted systems, IMO are more useful systems for conducting tasks, such as walking, searching for downed animals, and big game processing as well as camp chores.
I do have to disagree with your comment about not having as much light output. The Wensel's light (according to their web site) offers 60 lumens of light, same as the high output of the light I referenced. In my experience 60 lumens of light is far too much light to use in the woods for most activities. Granted now 60 lumens is rather a small amount when chasing the bad people down an alley, but that's not what we're talking about here.) For use in the woods you want flexibility of light control that translates into maximum battery life time.
As for batteries, both units utilize the same battery; the CR 123 Lithium battery.
FYI, in fairness to the comparison between the two products the product I'm recommending is about $25 more than the Wenzle's product. And in answer to your next question, "No I've not got a vested interest in the sale of either light". I just think it's a superior product, a "COOLER" light.