I've been updating the OP with all your changes.
Not to drag on this thread any longer but I've been playing around with an option over Low Kick and I want QC's thoughts on: Counter.
I'll preface this with I know running Counter on a sweeper in this day and age is heresy but I think it's probably Zoroark's only decent option outside of Low Kick and Low Kick is kinda shit anyway. Low Kick hits Bisharp, Tyranitar, and Heatran but that's pretty much it. With Steel-types being neutral to Dark and all other OU Dark- or Steel-types either being light-weight (Umbreon) or neutral to Low Kick (Mandibuzz), Low Kick is just there because Zoroark's 2nd best coverage move is Return, which I tried recently because it hits Fairy, Dark, & Fighting and was greatly disappointed to see it never KO anything at +2.
Counter of course demands Focus Sash be intact, which means smart use of Illusion to force switches, but it lets Zoroark clear Foul Play Mandibuzz/Umbreon (+2 Zoroark Counter can OHKO Max HP Mandibuzz on Foul Play), Azumarill, Mega Mawile, Landorus-T, Conkeldurr, Terrakion, and pretty much any physical threat that Zoroark has problems with. You can even add Bisharp back onto that list should Iron Head not flinch. That's a hell of a lot more Pokemon than Low Kick but I'll also add that it's far less reliable as one stray hit makes the move go from more useful to completely useless. But, on top of clearing Zoroark's own checks, the team utility of having a revenge check to any physical sweeper that can still operate on 1 HP with its STAB priority is pretty damn nice; not great or even reliable but nice.
If we do anything with Counter, Low Kick is still the safer option and should definitely be listed as such. I don't mean to sound overly negative about Low Kick or overly positive about Counter either if I'm coming off like that, both options are coverage band-aids at best and sub-par ones at that so slashing them together doesn't seem like a terrible idea to me.