Comparison: Scizor VS Ferrothorn
(Ignoring Mega Scizor because it's Post-Game, also assuming you transfer a Ferroseed from a different game)
Defensively, Ferrothorn is superior to Scizor. Outclasses it in HP, defense, and Special defense. It's main drawback is it's incredibly low speed, however, since you're going to use them as stall Pokémon it's speed isn't really a big concern. It also has a good base 94 Attack, meaning that it could also do a reasonable chunk of damage to opposing Pokémon. Scizor is only superior in this case because of its typing, which gives it a neutral matchup to fighting instead of a weakness. Movepool wise, Ferrothorn gets an incredible utility movepool.
Scizor gets stall moves like Iron Defense, Toxic, Light Screen, Double team, Tailwind, and most importantly: Roost.
Roost gives Scizor a huge advantage because it now gets a direct recovery move, which Ferrothorn does not.
However, Ferrothorn gets Iron Defense, Stealth Rock, Leech Seed, Spikes, Toxic, Double Team, Thunder Wave, Ingrain, and Curse.
Ferrothorn also gets incredible STAB moves, with it's speed boosting Gyro Ball to (usually) full power. It also gains Power whip as another strong option.
Go for Ferrothorn for defence, Scizor for offence.
Scizor is meant to be an offensive sweeper, with moves like Swords Dance, 60 BP Pursuit and Bullet Punch, X Scissor, Brick break.
But on the other hand, Ferrothorn is built to be a defensive wall. Excellent hazard moves, passive recovery options, it has it all.
Movesets:
Scizor @ Life Orb / Scizoritite (Postgame)
Ability: Technician
EVs: 248 HP / 252 Atk / 8 SpD
- Swords Dance
- Bullet Punch
- X-Scissor / Roost
- Pursuit / Aerial Ace / Brick Break
(Use any pairing of the 5 offensive moves depending on which one suits best)
Ferrothorn @ Leftovers
Ability: Iron Barbs
EVs: 252 HP / 4 Atk / 252 Def
Relaxed Nature
IVs: 0 Spe
- Toxic
- Leech Seed
- Gyro Ball / Power Whip
- Protect/ Spikes / Stealth Rock
