rather than striding so far forward, perhaps you could try to push up through the heel of your lead foot. Imagine that you are drilling the heel into the floor and then push up through it. You should feel that.
I tried what you said, I must be doing it wrong, because I couldn't quite tell. What I've read (and experienced) is that the larger lunge targets the upper areas more - the hamstrings and the butt (and that elusive little area where the two meet), while having legs closer together will work the quads more.
just a suggestion.
Maybe I'll try it in a few days once I walk off yesterday.