I disagree that cats are in the laminar flow regime. They may be traveling at a speed where one would expect laminar flow under ideal conditions, but there is nothing laminar about the the flow near the air-water interface. Too much entrained air and eddies from the wave action. And those eddies will be deep enough to affect a portion of the dagger and rudder, so I'd skip prepping for laminar flow on those, too. Another problem with laminar flow is that it separates more easily than turbulent flow and separation is the big drag producer.

Once you accept that laminar flow is, at best, a fantasy and, at worst, undesirable, then you can move on to the smooth vs "rough" argument. Personally, from the journal articles that I've read, I see turbulence as sort of a microscopic version of separation. With separation, there is an adverse pressure gradient that builds up near the surface due to viscosity, and when this pressure reaches a certain value, the flow separates from the surface forming a coherent eddy structure behind the object. The way to prevent this from happening is to induce randomized, turbulent flow which brings energy down closer to the surface. Well, a similar thing occurs in the boundary layer of fluid. A coherent vortex structure builds up with vortices forming and bursting in periodic fashion and the thinking is that a randomized "rough" surface prevents this coherent vortex structure from forming.

But, there's arguments both ways, some more supported by experimentation and theory than others.

Not that I'm worried about a bit of this on my cat.