I can vouch for this advice. Blitzkrieg gave me this advice a while back and it works very well. I've had a number of successful warrior rushes and gotten nice land because of it. The only time I wasn't successful is when I was probably too far (still have trouble judging what is "close enough"). I realize warrior rushes aren't possible past Prince, but it gave me the opportunity to practice. I still play on Noble but I'm pretty sure I should move up. What I find encouraging for myself is that the great advice being given here are things I already do well (well I still have problems with city placement).