I tried enabling Leader Rate Randomization in game option to "medium.
I discovered all leaders' Rates are then randomized.
Guess for game and historical reasons it could be interesting to have the chance to randomize rate values only for one star leaders, expecially "generic" leader not having a proper portrait.
It's unhistorical & unrealistic to have all "generic" one star leaders sharing the common 1-1-3 rating.
At the same time, ratings for major leaders should not be influenced by randomize leader rating option: most of them are men that already reached the top in their career.