Sableye should be higher, I agree. I've been running a sort of custom SpD Snarl set and it works absolute fucking wonders.
Gligar is basically a pile of shit (sorry brobat). I don't give a shit how well it can tank hits, basically every boosting sweeper in the tier can set up on it. There are so many better choiced for Stealth Rockers. It shouldn't even be relevant in a tier with as many good Stealth rockers as UU has. (Swampert, Rhyperior, Crustle, Registeel (meh), Cobalion, Sui Aero, Loldol, Uxie, Azelf, Mew, Empoleon, etc....) Unlike all of these pokes, Gligar can only set up SR and wall and nothing else. In nearly all of the roles it's supposed to be able to fit as a niche, it is outclassed. (Ex. outclassed as a pivot by Cobalion, outclassed as a wall by stuff that can actually do shit). There are far better defensive walls in UU with far better Utility, most namely QWILFISH, who can't get set up, can lay two very important types of hazard, can taunt, spread paralysis, pseudo-spin block, deal decent damage with base 95 attack, has reliable recovery in Pain Split, has an awesome ability, has key resistances to Fire and Fighting, has actual variety in its set so you can't know as soon as you see it that it's running U-turn/Toxic/Roost/SR, etc.
^ That right there is the definition of Utility. Having SR and U-turn is not Utility.
In other news about things that are shit, I'd like to talk about some of the "Ambipom isn't as shit as you'd think" arguments.
Actually, I'm not going to talk about the arguments, I'm just going to show how some common leads fair against Ambipom. These stats are taken directly from the lead stats.
1) Mienshao - In a good player's hands, lead Mienshao will most likely be scarfed. Mienshao can easily survive a Fake Out and then either obliterate Ambi's face with a HJK or U-turn out on the switch, gaining most of the damage taken back and building momentum as well as maintaining the switch advantage. In the optimal situation that the Ambi user predicts the U-turn and stays in, the Mienshao user can go into any wall with Utility or set-up moves and begin to set up.
2) Bronzong - Ambipom can do basically nothing to Bronzong. Beat Up does around 40%, and Gyro Ball is easily an 2HKO. Presuming the opponent goes for Beat Up three times, Bronzong will have gotten SR up and Gyro Balled once. The Life Orb recoil will be enough to finish off Ambipom and make it a double down, giving the advantage to the Zong user.
3) Froslass - Admittedly helpless if Ambipom happens to be carrying Beat Up and is Jolly. You wouldn't lead with a Lass if you saw a Pom though, just like you wouldn't if you saw a Cincinno.
4) Crobat - Easily outspeeds. Inner Focus prevents Fake Out from being effective at all, and Return does no more than about 55% optimally. Band Crobat straight up OHKOs, and Stallbreaker wins as well.
5) Victini - Scarf Victini shrugs off a Fake Out, smashes face with V-Create. (see Mienshao)
6) Azelf - Azelf outspeeds, can either just blow up for the double down or get SR up if it chooses. Offensive variants can OHKO after the LO recoil from Fake Out with Psychic or Zen Headbutt around 90% of the time.
7) Sableye - lol
8) Ambipom - lol
9) Swampert - Can take hits for days, smash with an EQ, burn with a scald, or just set up rocks and go from there.
10) Darmanitan - Scarfed Darm takes a Fake Out and smashes face. (See Mienshao and Victini)
11) Mew - (See Azelf)
12) Rhyperior - Low Kick does 40%. With even a tiny bit of investment, Rhyperior can just set up SR and KO with EQ.
13) Chandelure - Scarfed Chandy easily OHKOs with Fire Blast.
14) Gligar - Sets up SR, does whatever it wants as Ambipom can do nothing to it. (Mienshao, on the other hand, can wreck its face off much better.) (note that being an ambipom counter does not in any way make Gligar good.)
15) Abomasnow - Protects on the Fake Out. Switches into something to piss on the Low Kick and goes from there.
I could keep going and going, but you get the idea. Ambipom, if anything, is supposed to be a good lead, but it doesn't win against more than one (froslass) of the Top 15 leads in UU. In other words, it's shit.