I have run a Star Wars-vs-Star Trek universe for two or three seasons. Really fun! But it was a lot of work typing in all the names and other info for all my players, as I have minor leagues and the works. After doing all that work, I didn't feel like spending much time on logos etc. Maybe this year I will.
For Trek and Star Wars, team names came easily: the Starship Enterprise, the Hoth Rebels, the Alderaan Ghosts, etc.