That's a solid bulky offence, but there are a few notable issues. I'll break down the changes here:

I) Firstly, running defensive Garchomp solely to have a second hard check to Mega Scizor is unneeded, as max speed Heatran can easily switch in to most Scizor variants lacking superpower and revenge kill it. I feel that it also isn't really needed as a bird check as well due to the fact that Rotom-W is present and can easily check M-Pinsir and Talonflame. Pokemon like M-Loppuny and Kyurum-B -- amazing offensive Pokemon with nearly 0 defensive utility, really appreciate momentum cores to get them in safely. Finally, earthquake Zard-X is becoming much more common, so earth power Heatran as a Zard-X check is shaky in the current meta at best.

Therefore, I feel that running an offensive Landorus-T>defensive Garchomp is ideal, as it provides a slow U-Turn for K-B and Lopunny to get in safely, in addition to the fact that this team really struggles with Clefable, as Heatran does not beat Clefable if it gets paralyzed on the switch. An offensive Landorus-T can 2HKO Clefable, in addition to breaking down otherwise solid answers like Quagsire and Amoonguss. In addition, it still provides a much better (albeit easily worn down) Zard-X check, and a satisfactory /bird/t-tar/drill check. I do recognize that this change makes Bisharp more difficult to deal with; however, I feel that Rotom-W+Tangrowth collectively can deal with is sufficiently (not to mention that loppuny can just revenge kill it). In terms of the spread, outrunning timid Volcanion is needed in my view, as it really threatens the team from a defensive standpoint (although volcanion has so few reliable checks that adding a mon on this team JUST to check it just opens more holes then it closes). I advise this spread:

Landorus-Therian @ Earth Plate. OVER Defensive Garchomp.
Ability: Intimidate
EVs: 72 HP / 252 Atk / 184 Spe
Adamant Nature
- Earthquake
- Stealth Rocks.
- U-turn
- Smack Down

I feel that this team gets overwhelmed by spikes (especially tangrowth), so a way to pressure spikes stackers (skarmory epsecially) without switching out and losing momentum (and being spiked on) is definitely needed (and smack down still targets birds well). Max attack adamant is nice to actually 2HKO ferrothorn and Clefable (meaning you aren't spikes and setup bait), which is needed I feel. In general, this team is pretty boned by stall and fat builds (like quagsire, skarmory, clefable teams, etc.), and this Landorus-T really helps break them down (can deter Sableye from switching in, getting up rocks; 2HKOing common answers on stall like Quagsire, etc).

II) Thunder wave>Will-O-Wisp on Rotom; run 88 speed on Rotom-W.

This allows Rotom-W to outrun 252+ speed Crawdaunt. This is really important because having to rely on Tangrowth solely to check Crawdaunt means that its overall defensive utility is greatly diminished (bye assault vest). The lost defence sucks, but the Crawdaunt hype is real, so outrunning it is important. This is also nice to outrun 252+ speed Azumarill (rare but still), which is nice as you don't have to rely on Tangrowth to check it only. T-Wave I feel is needed, as an offensive Landorus-T really doesn't cut it for solely dealing with Zard-X, so T-Wave on Rotom-W is nice to cripple it completely. Plus, wisp targets don't really appreciate being paralyzed anyways. This is the new set.

Rotom-Wash @ Leftovers
Ability: Levitate
EVs: 248 HP / 144 Def / 28 SpD / 88 Spe
Bold Nature
IVs: 0 Atk
- Volt Switch
- Hydro Pump
- Thunder Wave
- Pain Split

III) Healing wish>Ice Punch on M-Lopunny.

Ice punch is cool to kill fat grounds, but honestly, this team has Kyurum-B and Rotom-W paired with pivots, so it's really not needed here. Furthermore, it's not like ice punch targets aren't easily worn down anyways (Lando+Chomp are really easy to wear down honestly), and it's not like ice punch breaks hippo anyways. Both options above are better here, as as it stands, this team can still get overwhelmed by hazards and residual damage fairly easily (wisp flame on rotom, scald burn on tangrowth, etc.), so healing wish provides some awesome team support for Tangrowth and Rotom-W alike. In a stall matchup, it can really help Lando out if, for instance, it gets burned by M-Sableye. Power-Up-Punch can be used here as well to help break down Pokemon like Hippodown and Skarmory, but I feel that the utility healing wish provides for this team, and any bulky offensive team in all honesty, is more worthwhile to have.

Optional: Rocks>Earth power on Heatran; Knock off>rocks on Landorus-T. Worsens the volcanion matchup (having to rely on rotom-w to check volcanion? lol), but allows lando to soften defensive Pokemon for Loppuny to pick off. Not 100% sure about this change, but I thought I'd mention it anyways.

Overall, this team's main problems included the fact that there were multiple Pokemon with the same role (having 2 M-Scizor hard checks, 3 dedicated bird checks namely), meaning that the team failed to include a means to break down fatter teams. Issues that I can potentially see with this team include facing hazard stacking cores (mega zam+spikes is really threatening) as it just makes Tangrowth not a check; however, the opportunity cost of adding a dedicated solution it too high in my view (the other mons are fine, no need to make excessive changes). Solid bulky offensive team and good luck, have fun testing!!! :D :D


Importable for new team!
http://pastebin.com/mPr33Mw2

Thank you for reading and have a nice day!