Hi, one problem that I noticed is that there can be too much pressure put on Ferrothorn throughout a match. Ferrothorn is relied upon to take Dragon-, Water-, and Electric- attacks. This is compounded by the fact that half the team is weak to Electric attacks, and Scizor is your other Steel type that can be easily baited into using Bullet Punch to be Magnezone fodder.
I suggest changing
Spikes to
Leech Seed or
Protect, however I suggest Leech Seed. This team, I find, if is not bulky enough to utilize Spikes to its full capacity. Also a lack of a Ghost-type means that 4 turns of setup can be wasted if the opposing team has a spinner. This change will allow Ferrothorn to heal some damage throughout a battle, and also heal it's teammates. In addition, if your opponent switches in Magnezone into Ferrothorn then it will be set-up fodder. I suggest changing the item from
Leftovers to
Shed Shell. This change in item makes Ferrothorn less bulky, however if it uses Leech Seed this problem is somewhat mitigated.
Another problem that I see is that the whole team has a weakness to Strong fighters (Terrakion, Lucario) after Gyarados dies, which with a prevalence of Stealth Rock and sometimes the lack of Starmie spinning can easily cut down Gyarados' health. To somewhat remedy this I suggest
choice Scarf over choice specs. This change allows you to revenge SD Terrakion, Neutral DD Dragonite and sometimes Gyarados', Virizion, and the like. Also, the surprise aspect is helpful as long as you hide the fact that Politoed is Scarfed.
Another problem I see is that there is no safe Electric switch in. To help with this I recommend switching Gyarados to Landorus. Now it can be Choice Scarf Landorus if you don't want Poli' to be Scarfed.
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The last rate is a bit weak, because I haven't test that change.