Well, first off, having two Stealth Rock setters is a bit wasteful unless your team for some reason or another REALLY relies on having Rocks up, and I wouldn't consider that an absolute necessity on most teams. You could replace Gliscor's SR with Swords Dance, U-Turn or Protect.
Zapdos' spread seems a bit confused. First of all, that moveset wants to be a bulky sweeper, not support. And then its EVs are fully defensive, but its nature boosts speed. It looks like your trying to spread your Zapdos a little thin, having it be bulky, but also fast, but also capable of taking out targets. If you try to be a jack of all trades, you'll end up being a master of none. First, think about what your team needs most out of this Zapdos: a full tank, or a bulky sweeper that can remove threats and allow either Latios or Scizor to sweep the rest of the game.
If you want a tank, get a nature that boosts one of its defenses, and give its moveset some more utility. Thunder Wave is a good option, as it can completely cripple a fast, powerful sweeper, and other options are Tailwind for speed control or even Whirlwind for phasing, although that's a bit more niche. Volt Switch is another good option for momentum, and I would keep HP Ice to threaten common Pokémon like Lando and Garchomp. You could keep Heat Wave for Scizor, but Latios already has HP Fire, so I wouldn't. You can still threaten Scizors out by feigning a Heat Wave, if you need to.
For offensive Zapdos, I would suggest keeping Timid with at least 184 EVs in speed to outspeed Landorus, then the rest can go into defenses. Unfortunately, no amout of SpA investment can OHKO Lando or Garchomp, so investing in SpA for those two isn't very productive since HP Ice 2HKOs either way.
A disclaimer: I may not be the best to take spread advice from, though, since outside of ubiquitous Landchomps, I'm not really in touch with the OU metagame atm, so I can't tell you which threats you really need to watch out and prepare for.
