Much of this depends on the position of the bass in relation to your hand. If you play the bass right up under your chin you need to somehow shorten your arm's length in order to facilitate plucking. If the bass is swinging down by your knees, the opposite is true. You have to stretch as far as possible just to reach the strings. Of course, this is extreme for the sake of the contrast, but how you choose to make an arm consisting two long segments separated by an elbow, a wrist that's capable of a wide range of motion and fingers which you use to operate the instrument is a personal decision.