Durant
Your current set is walled by Steel types, so Superpower > Iron Head. You lose out on STAB but you get better coverage in general, other than that no problems.
Chandelure
Well I don't know what this Over Heat move is, but I certainly haven't heard of it... anyway two fire moves on a specs set is kind of stupid as you'll be forced out by the switch in anyway, you're not sweeping anything so you might as well get off a heavy hit. I'd go either Trick or Hidden Power Fighting > Flamethrower, I prefer Trick as Hidden Power isn't even 2HKOing Porygon or Snorlax and nobody uses Houndoom anymore.
On the other hand if you take my later suggestions you could always go with the Choice Scarf set, it's the same moveset & EV spread but with a timid nature.
Slowbro
No suggestions, except maybe Fire Blast > Psyshock, not necessary but it's an option.
Amoonguss
Another team with no hazards, oh dear. Anyway I love Amoonguss but you could probably replace it with Roserade for those awesome spikes.
Roserade (F) @ Leftovers
Trait: Natural Cure
EVs: 252 HP / 120 Def / 136 SDef
Calm Nature (+SDef, -Atk)
- Spikes
- Giga Drain
- Sludge Bomb / Aromatherapy
- Synthesis
Mienshao
Well based on what I'm about to do, you should either make Chandelure or Mienshao scarf, I'd say Mienshao just because you need an awesome wallbreaker too. So here's the scarf set.
Mienshao (M) @ Choice Scarf
Trait: Reckless
EVs: 4 HP / 252 Atk / 252 Spd
Jolly Nature (+Spd, -SAtk)
- Hi Jump Kick
- Stone Edge
- Aerial Ace
- U-turn
Porygon-Z
Yep. You now have another scarfer, so unless you're pulling a Mew you should replace this. To not screw up your synergy there's another Normal type I'd like you to meet. Snorlax :] he sponges hits from Chandy all day, & checks most special sweepers in the tier that Roserade can't handle. There's a few sets he runs well, they all fit on this team tbh, but the offensive set is probably your best bet. Go look at Smogon if you want the others.
Snorlax (M) @ Leftovers
Trait: Thick Fat
EVs: 80 HP / 252 Atk / 176 SDef
Adamant Nature (+Atk, -SAtk)
- Return
- Crunch
- Earthquake
- Pursuit
