In online leagues, especially with fictional leagues, you don't have the instant recognizability of the simple, overlapping "N Y" or the red "B" that the Yankees and Red Sox have gotten away with for decades, simply because most teams are made up and recognition takes time.
That said, I guess that the logos with both nickname and origin would be just as popular as such logos are in college sports, where a very high percentage include name and origin(College name).
My 2 cents.
