Yes, Levitation the SPELL does NOT required Bat Wings to work, but however, this is a weapon proc, and therefore never, ever, requires components anyway :-/
I'm not a warrior but I play one on tv. Just kidding, I have an SK that has had 3 seperate whips in his 12 levels(Packmaster's Lash - sucks bad, Tentacle Whip - sucks for the most part, and the Phosphorescent Fiber - not bad). I have also seen a couple other whips in action that I don't remember the names of and the ONLY one that stunned was the Gnoll Hide Lariat. There might be others that do but I think you are misguided on every whip stunning. You may naturally be getting the stun with the damage done or confusing it with the effect of a bash.