The logic is based on the drop rates of different rarities. The number of packs is a consequence.
You have 1% chance of getting a legendary. So to have a "guaranteed" drop you need to open 100 packs in a single transaction.
We cannot guarantee 1 legendary NFT if you open 25 packs. Because the probability is still 1% and we cannot mint 1/4th of a legendary card.
This does not change the fact that you can get 1 legendary NFT opening a single pack. Just the odds are very very low.
Maybe the translator made me misunderstand it, if I have 25 packs, will I be able to use the recruiter that increases the % of distances? Because I understood that in order to use it at least you have to open +100 packs,...
There is no recruiter that increase the drop percentages. The new recruiter guarantee that you receive at least the percentage described here:
So if you open 100 pack with the new recruiter you will get for sure 1 legendary item.