Arlo is one of the three leaders of Team GO Rocket in Pokémon GO. You can find them by defeating the GO Rocket Grunts team on captured PokéStops. You will need to find six mysterious components to create a rocket radar. You can equip it with your bag and use it to locate one of the bosses. When you find Arlo in a Leader Hideout, you must defeat them to clear the Hideout.
Arlo now has three Pokémon in its lineup that you must defeat during battle. You have a handful of options at your disposal for fighting it, so be sure to keep a rotating list of compelling choices to use during engagement.
First Pokémon
The first Pokémon is Mawile, which is of the Steel and Fairy type. To defeat this Pokémon, you want to use a Fire or Ground-type Pokémon, such as Darmanitan, Flareon, Arcanine, Excadrill, or Rhydon. Either of these options would work against Arlo's first Pokémon, but you might want to choose a more durable Pokémon rather than relying on pure attack as your first option.
Second Pokémon
The second Pokémon in Arlo's list can be a Charizard type Fire and Flying type, Blastoise type Water, or Steelix type Steel and Ground. All of these Pokémon vary in their types, which makes it a bit difficult to know the best approach to prepare for fighting any of these three.
Your best bet might be to rely on a Water-type Pokémon. While they aren't effective or stable against Blastoise, you can have them use different moves than the Water-type to damage him, and also use these grabs to take out Steelix or Charizard if you fight them. For the water types you can choose from Gyarados, Vaporeon, Milotic, Swampert, Feraligatr or Kingler. There are a wide variety of water types to choose from and use in battle.
Alternatively, an Electric type also works against Charizard and Blastoise, meaning you can use Magnezone, Jolteon, Ampharos, or Electabuzz. The downside to using an electric type is that they are going to be extremely weak against Steelix. You might only want to use one if they have a secondary attack that they can reliably use against a Steelix.
Third Pokémon
The last Pokémon Arlo could use against you is Dragonite, a dragon and flying type, Salamence a dragon and flying type, and Scizor an insect and steel type. You have a bit more consistency here than with the other Pokémon choices.
Dragonite and Salamence share the same typing, so you can use a Dragon, Rock, Fairy, or Ice type during this fight to knock them down pretty quickly. You can choose to take Garchomp, Flygon, Gardevoir, Clefable, Lapras or Cloyster. Either of these options would be good against these two.
Although Scizor is a Steel type, they are resistant to the Dragon, Fairy, and Ice types, but not the Rock type. You might want to rely on a Pokémon with Rock-type abilities or a Rock-type to fight any of these three, such as Armaldo, Kabutops, Solrock, Lunatone, or Probopass.
You'll need to think about what type of Pokémon you want to use against one of these different sets. You want to use a general attack set, focusing on what resists the Pokémon to make yours last the longest. It's tempting to find a Pokémon that can consistently use super effective attacks, but Arlo's roster is blessed with a lot of health.
It's an attrition game, you want to last as long as possible. The higher the defense and overall resistance of your Pokémon, the longer you can stay in a fight.
