I don't see why the two are mutually exclusive. I could just make a line with any two traits at either end but if if the two are unrelated to eachother then little in the way of a meaningful result can be obtained. Say for example that I make a line looking at the "reddishness" versus the "greenishness" of colors according to their color decimal code. Highly different colors would appear side by side, such as black and white or brown and pink, while other colors that are different but more similar to eachother than those examples would appear further apart such as in the case of blue and magenta.
Similarly in the case of this op you would have people that focus highly on both (who would generally be considered the best debators) in the same spot in the line as people that put little effort into either and just spout a stream of consciousness (generally considered thr worst debators).