Rate my OU bulky offense team

Question

Landorus-Therian @ Leftovers
Ability: Intimidate
EVs: 252 HP / 164 Def / 92 Spe
Impish Nature
- Stealth Rock
- Earthquake
- U-turn
- Toxic
Get up rocks and u-turn out.
Heatran @ Leftovers
Ability: Flash Fire
EVs: 252 HP / 232 SpD / 24 Spe
Calm Nature
- Magma Storm
- Earth Power
- Taunt
- Toxic
Trap and cripple with toxic.
Slowbro @ Heavy-Duty Boots
Ability: Regenerator
EVs: 248 HP / 252 Def / 8 SpA
Relaxed Nature
IVs: 0 Atk / 0 Spe
- Future Sight
- Scald
- Slack Off
- Teleport
Physically defensive pivot, pressure with fututre sight.
Melmetal @ Choice Band
Ability: Iron Fist
EVs: 252 HP / 252 Atk / 4 SpD
Adamant Nature
- Double Iron Bash
- Thunder Punch
- Earthquake
- Ice Punch
Wallbreaker.
Ferrothorn @ Leftovers
Ability: Iron Barbs
EVs: 252 HP / 4 Atk / 252 Def
Impish Nature
- Stealth Rock
- Spikes
- Knock Off
- Thunder Wave
Annoying spike setter.
Dragapult @ Choice Specs
Ability: Infiltrator
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Draco Meteor
- Flamethrower
- Shadow Ball
- Thunderbolt
Clean up.

Comments

These descriptions don't say much we couldn't figure out ourselves. Can you say more about how the team members support each other, and some of the unique choices on the team (ex: SR on two mons, no Leech Seed and no STAB on Ferrothorn)?
The team is more defensive than typical BO in my view, and it's also extremely slow apart from Dragapult (which also happens to be your wincon). I don't think Ferrothorn suits this team but maybe you could give more explanation about that.

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Not a team issue but it'll be better to add line breaks after each pokemon next time. (Its easier to read that way)

Answer 1

Your team is quite weak to dark types and very slow. Ferrothorn doesn't fit anywhere on this team. You already have 2 steel types and you already have an entry hazard setter.

Ferrothorn -> Heracross

Heracross helps solve your dark type weakness, quite fast and a powerful sweeper with boosting moves.

Heracross @ Flame Orb
Ability: Guts
EVs: 4 HP / 252 Atk / 252 Spe
Jolly Nature
- Close Combat
- Megahorn
- Swords Dance
- Facade

Close combat & Megahorn as STAB moves. Swords dance to set up and facade to be boosted by guts and it's flame orb.

Slowbro -> Tapu Fini

Tapu Fini @ Leftovers
Ability: Misty Surge
EVs: 252 HP / 48 SpD / 208 Spe
Calm Nature
- Calm Mind
- Scald
- Moonblast
- Taunt

Adds a pretty quick specially defensive sweeper to your arsenal. Calm mind to set up, Scald and Moonblast as STAB special moves. Taunt to stall a little bit.

Comments

Ferrathorn might not fit here, but what does Heracross contribute towards speed control?  It's unranked in the Viability rankings, very niche and outclassed by Buzzwole and Zapdos-G as a Fighting-type. Its speed tier is nothing that great, so do you have any reasonings? Also, what does Tapu Fini over Slowbro achieve for the team except for the "specially defensive sweeper" line?