Gotta love the half stories... One of the common mistakes made is to not encapsulate the end grain, or joint surfaces or drilled holes.The replica of Henry Hudson's boat, Half Moon, was built that way, and they had rot problems soon after building. I recall they used a lot of pine, which rots quickly. I think a wooden boat not encapsulated will probably last longer than one encapsulated!
I friend had a Beetle Cat with a beautifully varnished tiller, probably at lest seven coats, and recoated annually. Once, sailing, the tiller just broke in half! Turns out the only thing left was a thin, outermost layer of wood and the varnish. It had rotted out and was hollow, with no outward signs.
So research each of those and discover the more likely truth. There are in fact boats built this way and components built this way that have been in service without any degradation for many decades.
dj