>>17720033Those servers are used to store pokemon, not generate them like the game.
When you "Upload" pokemon, what the 3ds does is
Sends a message to the space that belongs to your NID with instructions to save the information of that pokemon.
The server creates a file of that pokemon's information and saves it
Your Game deletes the pokemon from your save (Because it's just an object within an array)
When you "Withdraw" your bro, the server sends instructions to the 3ds+Game to create an exact duplicate based on the information based on the server your pokemon are stored in.
Stats and names don't get changed.
The only possible thing that could go wrong is a connection error that can result in losing your pokemon if your game didn't save.