In choral settings it is a little more relaxed about what ranges are needed and what words are used to describe the singers in them. Usually singers in choirs don't have such a need for a very soloistic or virtuosic approach to singers and thus have a slightly smaller range. In opera it is pretty much demanded that you have close to a two octave range or more, Yet you'll find in a lot of choral arrangements for singers that the range for each part lays closer to an octave and a half.
This shortening of the range usually takes place on the upper end of the register because that is the part that takes more time to develop and thus more people don't end up with that part of their range. For a baritone this means that you should expect most of the baritones to have a range from G2-D4, a fourth smaller then what is demanded for an opera singer.
The other issue that you have found is the descriptions used for the singers in the different genres. Because in choral singing you are usually singing in so many different styles you learn to create many different sounds and to produce many different effects as a group and as a soloist. While you do still maintain your individual timbre you will have to compromise to develop a group sound and because of this they don't usually don't describe sections of the choir to have different timbre inherently.
Besides issues with choral singing vs opera singing, both will involve looking at and evaluating the tessitura of the singers aka The average range. Tessitura is the word used to describe the part of a singers range where the singer can and will sing most of the notes that they sing. A good example of this is looking at the difference between a tenor and a high lyric baritone. The tenor is described as much because he can sustain singing in the upper part of his range vs the baritone which does not. They both have light and high voices but one of them belongs to and resides in a different pitch world most of the time vs the other.
I hope this really long post helps out, let me know if you have any questions.