The trick of optimizing games is to off-load as much as the simulation from the computer into the user's brain, which is MUCH more powerful and creative. Implication is more efficient (and richer) than simulation.
During development, when we first added Astrological signs to the characters, there was a discussion about whether we should invent our own original "Sim Zodiac" signs, or use the traditional ones, which have a lot of baggage and history (which some of the designers thought might be a problem).
Will Wright argued that we actually wanted to leverage the baggage and history of the traditional Astrological signs of the Zodiac, so we should just use those and not invent our own.
The way it works is that Will came up with twelve archetypal vectors of personality traits corresponding to each of the twelve Astrological signs, so when you set their personality traits, it looks up the sign with the nearest euclidian distance to the character's personality, and displays that as their sign. But there was absolutely no actual effect on their behavior.
That decision paid off almost instantly and measurably in testing, after we implemented the user interface for showing the Astrological sign in the character creation screen, without writing any code to make their sign affect their behavior: The testers immediately started reporting bugs that their character's sign had too much of an effect on their personality, and claimed that the non-existent effect of astrological signs on behavior needed to be tuned down. But that effect was totally coming from their imagination!
The create-a-sim user interface hid the corresponding astrological sign for the initial all-zero personality you first see before you've spent any points, because that would be insulting to 1/12th of the players (implying [your sign] has zero personality)!
