If you roll a die the average is going to be half the dies value +1, so average roll for a d6 will be 4, a d8 will be 5, a d10 will be 6, d12 will be 7 ect.
What experience was, somewhere around 1000 rolls the rolls should of been 11ish on both sides, keep in mind these are the unmodified rolls I'm speaking of. so if you have plus 5 to hit and roll a 7 your total would be 12, I'm talking I only recorded the 7. The pluses are something the player has an effect on via stat gear spells what have you. If you want to say true RNG could be anywhere that's fine but the AI "rolling" a value that is 4 higher than the player on the regular is just down right unfair, and in this situation would be cheating.
And no I was not playing tactician mode. I was playing on balanced as I was hoping that would offer up the most authentic TT game play.