@ Black Pegasus, I suppose it really depends on your playstyle. A number of threads discuss favorite or least favorite traits. I suppose if the end goal "Monty Haul/number crunching" then you'd just play leaders that the veterans claim are the best trait combinations.
I tend to pick a leader and play him/her for at least a couple of games, and then play someone else. I imagine when I get to the point where some of the Vet's are at, I might enjoy the "RandomCiv" - that a number of them recommend.
It also seems to me, the Devs worked at balancing LeaderTraits + UU + UB, moreso than just attempting to balance each individual trait between each other.
You'll also find some trait combinations that don't exist, likely for balance?
I don't see any leaders w/ Philosophical/Industrious, or Aggressive/Protective... I imagine there are other combos that don't exist or are rare too.