So, if I understand it correctly, each character in the game is assigned a random number queue which is set-up at some very early stage. If the first number in the queue is, say, 70, then the first attack against this character will fail if it has a hit chance 60% but it will succeed if it has a hit chance 80%. Just as Linio and Tuco described.
If this is the case, doesn't feel unfair.