Do champion boxers have the ideal height/weight combo?

After Floyd Mayweather's championship fight this past weekend, I noticed he weighed in at 146 lbs, and he's 5' 8" tall. I realize there can be be lots of variation on an ideal weight for a given height, but I have to believe that's pretty much the ideal.

Boxers can't afford to carry much weight that isn't working for them, but they can't be any thinner either. Their height/weight combo is essentially aimed at survival — strong enough to destroy, fast enough to avoid getting destroyed.

It may be an unattainable goal for normal, non-pro athlete types like me, but it does tell me what's possible. Might be worth doing more boxing-type training, huh?