The "v" step over object animation is extremely dainty and not at all suitable for combat situations. I can't tell you how many times ive sprinted under fire up to a fence. then stopped and tip toed over it slowly then started sprinting again.
http://www.youtube.com/watch?v=bpATaC3CKMY
Heres an example of scaling different height fences and walls at combat speed.
I think in arma scaling fences up to head height or even a little higher should definitely be implemented because it is done all the time in real urban combat.