Are rescued buddies generated randomly as-you-go or as soon as you pick your character? (as-you-go means that if I reload a save before receiving a mission to rescue an unknown buddy, then the buddy differs each time. The other option means that buddies ARE randomly generated, but it is generated and set at the start of the game)
Or are buddies not random at all? (each character has their own pre-set of buddies unlocked in a pre-set order)

Thanks in advance