The main idea of the Spectrum is that the further away from the center you get, the less control the wearer has over the power source. Rage and Violet are MEANT to read as vessels for the emotion they represent. Rage and Love are meant to consume them or, as it's explained in the books, fill a void within the person.
The remaining corps, then, are controlled by their emotions to varying degrees. Breaking it down by the (excluding Green and Yellow which, as you've said, are pretty diverse, personality-wise):
The Orange Lantern Corps, as you've also said, is really only one individual, and by nature of being closer to the extreme end of the Spectrum, his ring should hold less of an influence on him than Red but more of an influence than Yellow. And this seems to be the case. However, regardless of this, the entire Corps is going to read like one personality because it is.
Blue Lanterns should be as individual as Yellow Lanterns, theoretically, because they are in the same place on the Spectrum. However, you also have to keep in mind that the selection process for these Lanterns is the most intense and thought out (when compared to the other colors). By the nature of these two points, they are meant to all share similar ideals. After all, it's a very exclusive group made up of the most hopeful and faithful figures in the Universe.
The Indigo Tribe should theoretically be as consumed by their emotion as Agent Orange. But we don't have a lot to go on other than that their membership seems to be the largest (again, contrasting the Orange Lantern Corps).
I personally find these various Corps to be extremely well planned and explained with reasons that fit the context of the story.