Parmandur
Book-Friend, he/him
The added randomness is nice, true, but it would slow down game play (albeit not a lot...) and could lead to even higher numbers, making even more times when he is unnoticeable.
Not terribly slowed down: and yes, it would be a wash mathematically in the long run, averaging out to the same numbers. However, changing the basic numbers is much more likely to cause problems with the game, by throwing things out of whack all around. Thing is, Rogues are supposed to be able to succeed by huge amounts on a regular basis: may as well ban Rogues rather than break the system so they can't do their thing.