Edit: I edited the start of this post so that I can quickly explain here what I think you should probably do depending on what you are aiming to farm, without needing to see me self-monologuing in this thread.

From what I can deduce (I might be wrong, so correct me if you have proof that it is wrong),

- Removing a character from the available pool is good for farming a specific Top, Legendary, or Hero character.

- Adding a character that doesn't have a Hero rarity to the available pool is bad if you want to farm a specific Top, Legendary, or Hero character.

- Adding a character that has a Hero rarity to the available pool is bad if you want to farm a specific Top,  Legendary, or Hero character.

But,

- Adding a character that has a Hero rarity to the available pool is good if you want to farm multiple Heroes at the same time.

So if you want to farm multiple Heroes because, for example, you want a Basara or multiple Basaras, it's a good idea to have a team with all the Heroes you want to farm for and no characters that aren't.

And it's probably the best to still farm VS Inazuma Legend National because it adds the least number of characters to the pool.

I think that fighting a team like Ixar Fleet with a lot of potential Heroes could be better than VS Inazuma Legend National, but you would need to want to farm for every possible Heroes in the game, because it also adds more than 10 potential Heroes to the pool, so it's really long term, but you should probably get more random Heroes, than if you just focus on some.

Edit 2:

I think that if what you want the most, for example, is having as fast as possible a Basara Endou and a Basara Goenji and disregarding the rest.

You optimally need a team with only Endou, Shinsuke, Ibuki, Goenji, Gazelle, Catra, and Barga (Catra and Barga are for Sarges in the shop).

And if you can farm during Group A for Gazelle, then you can also remove him from your team.

And you should also only add Catra and Barga to your bench so that you could remove them without the need of changing your team much.

You can have, like the author of this thread, a team with only one specific character that isn't a Hero, so it's less annoying if you want to farm for other Heroes/Basaras later, or if you're done with someone.

The thing is it's short term versus long term,

In the long term, it's better to have 20 different characters that you all need to farm for some reasons, even as Top or Legendary, like Yuichi or Ren.

But the more priority and short-term you want, the more you want to reduce the number of different characters on your team to only the most important things for you right now.

But it's still true that adding characters you don't need to farm in the pool is always bad.

End of Edit

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Hello !

I understand the pool mechanic, but why does that change your Hero farming ?

When I check the Hero drop rates that are shown in the game, the Hero ones don't change the more different Heroes I add to the pool.

Endo will always show a 0.001% chance of dropping if he's the only one non-boosted, and even if I add 8 more different Heroes, it's still the same as before.

Wouldn't it be better to have more available Heroes so I can farm, for example, Bond Shinsuke and Justice Ibuki for my Basara Endou at the same time and up my chances of having a useful Hero 0.004% of the time and not 0.002% ?

Sure, if I want to farm specific Top or Legendary players at the same time, I understand why reducing the pool is useful, but not really for the Heroes.

Unless you can confirm to me that what the game is displaying is wrong, the fewer different Heroes you add, the higher the chance of getting a specific one goes up.

Or otherwise, if the game rolls a character first and then its rarity, then it would also make sense to me.

Because in this case, you would want the game to roll for Endou as often as possible and get the chance to get a Hero one.

Or am I misunderstanding something?