Little, but huge, concern

[V.T. Marvin]

Sorry Darius, but the problem seems to be on YOUR side. As you may note, only the starting traits are somewhat random. But the subsequent ones develop largely depending on what you do (or not do) with your characters and whether your actions are in harmony with what their starting traits seem to predispose them to.
Therefore I would say that if you want to role-play your FMs, you just should actually role-play them. Look what traits you new FM already has and think about what such a man would likely do and act accordingly, rather than stick to your preconceived idea that the Faction Leaders first son will eventually become a secod Alexander despite the fact that he is dull/uncharismatic/langurous fat boy. Do not let your phiantropes to exterminate cities. Do not let your ambitious and able governors roam aroud backwater province with a hadful of troops. ROLE-PLAY and you will see that your FMs are starting to gain just the right traits that suits them (and usually also to your wishes).

P.S.- And be polite when askig anything from the Team. I personally understand your post as phrased in arrogant ranting, which is hardly conductive to make others to work very hard to fulfil your wishes.