That was one of my thoughts when i saw the fang release: really? they add in a bunch of aux arc stuff and they put in probably the best counter to aux arcs IN THE SAME WAVE!?
Nothing different for tailing a firespray (except scum kath) but tailing an arc or sf is way in his favor. Auto crit from the arc vs auto dodge....no fear.
Really only benefit the aux arc has vs fangs is potential side-stepping and still getting a shot. No aux arcs cant sidestep very well (i do it with wedge because of lightning reflexes, which is of course once)