wrote:
Is this idea commonly accepted?

http://www.oneoceankayaks.com/kayakpro/kayakgrid.htm

The final chart is the most revealing as it includes displacement, a
factor mentioned by another poster. Once you start loading up the hull
with a bigger paddler or extra gear (advertisers urge us to buy the
extra gear) the smaller boat slows down. However the displacement
formula starts to break down when the power:displacment ratio and the
length:beam ratio become large as they do on canoes, kayaks, and
catamarans. These craft easily slice though their bow waves. Here is
another example of often misapplied theoretical math. As the website
owner says (disclaims) you can't take those graphs literally. They are
only a rough guide to relative performance.

There are three important considerations, the hull, the paddler (source
of power), and the intended use of the boat. Canoe and kayak designs
are now so finely tuned to different uses that some fanatics own
several. It become a bit obsessive-compulsive trying to decide which
boat to take on an given route on any given day at any given season of
the year.