I have definitely NOT done any maths. (My skills at stats are minimal.)
I feel that using statistics can be fraught with the dangers of misinterpretation. Models with thousands of trials might lead to wholesale general patterns - but how many dice rolls does each player complete in a session/chapter? Or in an adventure? So a general pattern might need a health warning because it works with big numbers, but may not be replicated that often in play.
On the other hand, all information can be useful, so I am still keen to read the numbers. I don't want to sound too negative about something I cannot do well!
Keeping option B as a fix for broken maths, I am thinking a little about these possibilities
I think that the difficulty of the Council should be down to the people that the players are speaking to, not the skill level of the players. How experienced are players going to be with level 5 in a wide range of abilities? None of my PC have reached that yet in TOR1e games. So in this case, the LM needs to step up to the plate. Which is the purpose of my question of course !
E.g. Why not make an Easy Council one with favoured rolls, and a Hard Council one with ill-favoured rolls?
E.g. the first Failure changes the subsequent rolls to ill- favoured, until a tengwar can be spent to cancel that?