It depends on your grip size and the length of the handle of your racquet. I use a 4 1/2 with 2 overgrips and I agree it's too short. And if your racquet handle is longer (like an n90 or some Babolat's) it definitely will not cover the entire grip. I've always used tournagrip and am more than familiar with how to get the most out of it. I prefer a little overlap too but the short length of this grip demands minimal overlap.
BTW I agree with 808's technique.