The Speed EVs on Tar are meant to outrun Skarmory, so you can Stone Edge Skarm before he Roosts. Skarmory is now running 16 Spe EVs, which reaches 180 Speed. In that spirit, run 92 Spe on Tyranitar to accomplish that. It also outruns 16 Spe Metagross, which is also fairly common, allowing you to Earthquake before Gross Meteor Mashes or Earthquakes you. Also, why not put Pursuit on Tar? That way, you can trap all kinds of pokemon who don't usually threaten the Specially Defensive beast, such as Azelf, Rotom, Gardevoir, Alakazam, and Blissey. I'd use it over Aqua Tail, because you have Vaporeon, who can beat most Hippowdon, anyway.
Speaking of Vaporeon, why a Specially defensive variant when you have Tar and Bronzong? If you go with the standard 252 HP/252 Def/4 Spe Bold, you can run Hidden Power (Electric) in the last slot, giving you a very good counter to Gyarados and Infernape.
Ice Punch on Luke for Zapdos? You have Tyranitar for Zapdos, so you could just use Crunch there for extra coverage. Many Zapdos will be running enough speed to outrun Jolly Luke, anyway, and Salamence always runs a +Spe nature now.
The Fighting weakness is a big one here, so let's look at some common Fighting-type sweepers, as well
as sweepers who carry Fighting-type moves.
Infernape: Vaporeon can deal with most Infernape sets very well, so I don't consider him a huge threat.
Lucario: I don't think Forretress actually needs a Defense drop in order to KO him. He's kind of covered, I guess, but he could still cause problems.
Heracross: Though rare (indeed, he's on his way to UU/BL), if you do encounter a Heracross, it will probably destroy you. Most are Adamant Scarfers, so PoryZ can revenge kill him, but PoryZ doesn't trap Hera, so he'll just switch out. Bronzong is your best answer, but even he won't enjoy taking a STAB Close Combat or Megahorn as he switches in.
Machamp: Everyone is Machamp weak. I mean, everyone who doesn't run Slowbro is Machamp weak. There are things you can do to check him, though, most notably using a Ghost (Rotom or Dusknoir, because RestTalk Machamp carries Payback for Ghosts), or having someone carry a Lum Berry. Lum Berry is only a one-time thing, though.
Breloom: Breloom sucks to face, no doubt about it. You don't have a status absorber, and no Fighting resistances on the team means his Focus Punch will knock you around a lot. You can't even revenge kill him, since he hides behind his Sub all the time.
Scizor: Scizor carries either Brick Break or Superpower, and either way, this team doesn't take him well. He OHKOs Tar with Bullet Punch OR his Fighting move, deals massive damage to everything you have, and isn't very fast, so he doesn't care about Gyro Ball. Luke doesn't win against him either, since he can't OHKO, while Scizor can OHKO back.
So, you're going to need a surefire Scizor counter, as well as something that can deal with Heracross, Breloom, and Machamp. My suggestion? Remove Pory-Z for Rotom-H. You can use the Trick Scarf set:
Rotom-H @ Choice Scarf
Levitate
4 HP/252 SpA/252 Spe Timid
-Overheat
-Shadow Ball
-Thunderbolt
-Trick
Rotom-H is one of the best Scizor counters out there, OHKOing with Overheat while only really fearing Night Slash.
After Breloom has put something to sleep, he won't like getting hit with repeated Shadow Balls (don't use Overheat, since you'll break his Sub, and then be unable to KO him thanks to the SpA drops).
Heracross is NOT OHKOd by Overheat, so make sure he's taken previous damage before trying to take him on. Even if Hera is Jolly and Scarfed, max Spe Timid means Scarf Rotom-H will outrun him. Rotom is not a real counter, but he's a good check. Watch out for Night Slash.
Machamp can't Dynamicpunch a Ghost, and the RestTalk set will HATE Trick. Especially since Machamp has no need for Speed at all. Just make sure you don't switch into Payback, or the whole strategy fails.
DDMence causes a problem to this team. A HUGE one. After a Dragon Dance, Pory-Z doesn't outrun him, and +Spe Salamence outruns Jolly Luke, so you have no way to deal with him before he gets at least one kill. Vaporeon can take a hit, but can't do anything in return, making it set-up fodder for Mence. Your best bet is to find a way to lock it into Outrage, which will probably lose you a poke, and then Gyro Ball it with Bronzong, provided Bronzong is still around in the late-game. You lose Spin support and Spikes, but you could try running a Tank Metagross over Forry to deal with it.
Metagross @ Leftovers
Clear Body
252 HP/244 Def/12 Spe Impish
-Earthquake
-Ice Punch/Meteor Mash
-Explosion
-Light Screen/Stealth Rock
You already have Stealth Rock on Bronzong, but if you want to change him around a bit, you can use the Rocks here. Earthquake is necessary to prevent Magnezone from ruining your day, Explosion because it's Explosion, and Ice Punch for Salamence. Meteor Mash does an insane amount of damage, too, but it isn't as accurate. My preference is Ice Punch.
I hope I helped. Good luck with this!