Quick post since a small bit of Discord discussion brought this to mind.

Magneton @ Choice Scarf
Ability: Magnet Pull
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Thunderbolt
- Volt Switch
- Flash Cannon
- Tri Attack
I think it may be possible that Magneton has a slight niche as a Choice Scarf user due to its higher base Speed compared to Magnezone, which lets it outspeed more threats than a Scarf Magnezone would.
As seen in the image in the spoiler tab, Scarf Magnezone falls below a small but significant group of threats in terms of speed; getting outsped by base 115s, +1 Jolly Tyranitar, Alakazam, +1 Feraligatr, Weavile, and +1 Dragonite. Scarf Magneton being faster than all of those mons means that, at the very worst, it would do some solid damage so that something else can revenge kill them afterwards (or you do like 30% max to Raikou lol). Being able to outspeed and OHKO Feraligatr, Starmie, and Weavile while not being weak to Ice Shard is also a nice trait to have.
So why would you use Scarf Magneton over other Choice Scarf users with better speed, utility, and offensive capabilities? Simple, Magnet Pull. With the exception of Scarf Heatran, Agility Lucario, and Scarf Jirachi (all of which are rather uncommon sets), Scarf Magneton is able to outspeed and trap every Steel type in the tier, which lets it force damage on them and remove weakened ones. This lets Magneton trap Steel types that Magnezone would otherwise be afraid of, such as offensive Heatran and Lucario.
While the damage can be lacking due to not running Choice Specs, running Scarf Magneton alongside Specs Magnezone can help alleviate this issue, as Magnezone can trap bulkier Steel types like Scizor and Empoleon. Being able to trap what is effectively every Steel type in the tier can be very useful for teammates who would otherwise detest having to fight them, such as Calm Mind Latias. Latias resisting Fire and Fighting, while being immune to Ground, helps alleviate the problem of running two mons on the same team who share those exact same weaknesses. I think it's possible the three form a nice core.
That being said, this is a small niche, and one that I have yet to actually test out, so it is possible that what I have written here could all be wrong. Looking for new strategies has definitely been one of my favourite things to do in this metagame, so I do hope that this one will turn out well in the end.

Magneton @ Choice Scarf
Ability: Magnet Pull
EVs: 252 SpA / 4 SpD / 252 Spe
Timid Nature
IVs: 0 Atk
- Thunderbolt
- Volt Switch
- Flash Cannon
- Tri Attack
I think it may be possible that Magneton has a slight niche as a Choice Scarf user due to its higher base Speed compared to Magnezone, which lets it outspeed more threats than a Scarf Magnezone would.
Magneton isn't on this list, but it shares the same speed tier as Breloom, which still demonstrates the gap in speed between Scarf Zone and Scarf Ton.
As seen in the image in the spoiler tab, Scarf Magnezone falls below a small but significant group of threats in terms of speed; getting outsped by base 115s, +1 Jolly Tyranitar, Alakazam, +1 Feraligatr, Weavile, and +1 Dragonite. Scarf Magneton being faster than all of those mons means that, at the very worst, it would do some solid damage so that something else can revenge kill them afterwards (or you do like 30% max to Raikou lol). Being able to outspeed and OHKO Feraligatr, Starmie, and Weavile while not being weak to Ice Shard is also a nice trait to have.
So why would you use Scarf Magneton over other Choice Scarf users with better speed, utility, and offensive capabilities? Simple, Magnet Pull. With the exception of Scarf Heatran, Agility Lucario, and Scarf Jirachi (all of which are rather uncommon sets), Scarf Magneton is able to outspeed and trap every Steel type in the tier, which lets it force damage on them and remove weakened ones. This lets Magneton trap Steel types that Magnezone would otherwise be afraid of, such as offensive Heatran and Lucario.
While the damage can be lacking due to not running Choice Specs, running Scarf Magneton alongside Specs Magnezone can help alleviate this issue, as Magnezone can trap bulkier Steel types like Scizor and Empoleon. Being able to trap what is effectively every Steel type in the tier can be very useful for teammates who would otherwise detest having to fight them, such as Calm Mind Latias. Latias resisting Fire and Fighting, while being immune to Ground, helps alleviate the problem of running two mons on the same team who share those exact same weaknesses. I think it's possible the three form a nice core.
That being said, this is a small niche, and one that I have yet to actually test out, so it is possible that what I have written here could all be wrong. Looking for new strategies has definitely been one of my favourite things to do in this metagame, so I do hope that this one will turn out well in the end.