I get that the game wants to assign random traits to randomly generated characters, but I really think that there should be limits:
1: Characters marked as "historical" should only get the traits that are assigned. If I'm playing the GoT mod, I shouldn't have Ser Duncan the Tall randomly assigned the "craven" trait at the beginning of the game. If you want to keep the ability for historical characters to have a couple random traits for flavor, add a command that gives "trait=random" or something, that way you can say that the guy is Brave, Kind, and [Insert random one here]. Building scenarios and carefully building characters only to have the game randomly insert a bunch of nonsense on top of it is really, really aggravating.
2. Limit some traits from appearing in certain types of random characters: I get that the game only has so many marriageable females of the proper age at any one time, so if I crusade in and have to create dozens of new barons or counts in a day, many if not most of 'em will have random lowborn women as wives. Thing is, if you're marrying a random commoner and can therefore pick from any woman in the county, are you likely to pick a cruel, inbred, dwarven, hunchback? I'd be really nice to have the ability to tweak which events are more likely for random courtiers... If I'm asking for a random guy to command an army, why would weaklings even show up? I have enough inbred hunchbacks in my nobility, I don't really need more from the folks who are essentially random job applicants. Giving offices or command to lowborn should come at a cost, either in not getting the loyalty bonus you get for assigning an office to a vassal or in a bonus to giving a vassal command (something we currently don't have, but probably should... There should be reasons why you sometimes want to give command to Duke Incompetent instead of some commoner, but the game doesn't simulate this at all....). In return, lowborn should be vastly more likely to be of talent; these are essentially the knights or townsmen who were of great enough merit to gain the attention of a duke or king, after all. Making them 100% random seems to miss the point entirely. Summoning a random courtier is expensive; at least make it more likely than not that I'll get someone at least vaguely competent.
And really. Stuff like dwarfism is WAY too common. Only 1 in 25,000 (some studies suggest it may be as low as 1 in 100,000) people have it in real life (how many of you don't even know a single person with Achondropasia? Heck, how many of you have never even seen someone with it in person?), and many of them would have been killed as infants back in the day. Dwarven lowborn should be VERY VERY VERY rare, so rare that their inclusion in the game is probably unneeded. But back when retinue general spamming was around, I could create 20 units and be sure to have at least one, usually more, generals with dwarfism out of that 20... That's ridiculous. I know, I know. Tyrion Lannister is cool. But GRRM didn't make 10% of Westeros dwarves. Heck, the entire series of books has what? Two dwarves who aren't carnival entertainers? Then why do I have so many ruling counties or dutchies in my empire? Having a powerful duke have a dwarf as an heir should be a notable event. Instead in CK2 it happens CONSTANTLY.