Paddling resistance is primarily the sum of skin friction and wave-making resistance. There used to be technical articles published in Sea Kayaker that plotted both types of drag vs speed for commercial kayaks, but they were not measured values. Rather, they were the result of software - this can be good or bad, but the plots were not verified by experimental testing.
Re the two main components, skin friction is proportional to wetted surface area and velocity squared, i.e. it increases exponentially in a fairly predictable manner.
Wave-making resistance is less predictable since it is heavily based on details of hull shape, but it does increase with speed too. For a given displacement hull, wave-making resistance will increase rapidly over a range of speeds depending on its shape and length. The speed range is colloquially identified as the ‘hull speed’, although there is not a fixed point where the transition happens.
The transition happens at lower speeds for shorter hulls, i.e. longer hulls have higher ‘hull speed,’ which just means the transition happens at higher speed. At a given speed, wave-making resistance can be very high for a short hull, but significantly less for a hull that’s ‘long enough’ to still be operating below the transition point. In this case, the full resistance value will be less for the longer boat, which is the point of long skinny racing hulls.
At lower speeds, when a short and long hull are both operating well below the transition to high wave-making resistance, the shorter hull generally will have less total resistance because of its lesser wetted surface.
This is just my opinion, but I think for ‘normal’ paddlers at the 2.5 to 3 mph range, a 14 ft hull can be noticeably easier to paddle than a 17 ft hull. Not always, of course. This is the point of Brian Shultz’s article which is worth a read:
Choosing a skin-on-frame kayak - Cape Falcon Kayak (capefalconkayaks.com)
Having said all that, there are all sorts of reasons to opt for a longer hull, e.g. for choppy conditions, better tracking in the ocean, the ability to paddle fast when necessary, etc.
Sorry, this turned out to be pretty long-winded. I just now checked the Guillemot article, a much more complete explanation. I’m not sure I agree with the kinetic energy argument, but there are usually multiple ways to reason through fluid mechanic analyses - I’m definitely going to think about that.