Beery's Sub Commander mod allows you to choose your own patrol grid, if you so desire. The mod is stand-alone (and easy to install), so it won't wreck your game files, and there's a number of options to use as much or as little of the mod in your game as you wish.
http://www.beerymod.com/sh3.htm
Above is Beery's website. He also has some other nice mods, but not all are for beginners.