This has to do with how you choose to shape the lower ends of each of the shaft strips. The first shaft strip is joined with the blades. No worries there. The second shaft strip I usually make several inches shorter than the first strip, so it ends about halfway down the blade. Where it ends (the overall length) itself is a maker decision. I like how it looks with the end being about in the middle of the shaft.
The shaft strip pieces are sent with simple, square, full-thickness ends. They’re ugly. How to finish the lower end off such that it looks good as part of the lower end of the shaft, largely below the bend and largely at the upper end of the blade is the largest design decision in making your paddle. It comes down to a point. Do you want a long taper ending in a sharp point? Do you want something short, ending in a rounded shape? I’ve done tapers both ways, and basically have yet to find a shape I did not like.
Specifics. I think running the full length and full thickness of the shaft strips through the bend is a good thing. That said, you have about eight inches to work with below the bend. The fifth (top) piece is the shortest. This piece may just barely extend into the bend area, depending on how you position this top piece.
The tapered point of each piece will likely be close to the pieces above and below. You can work the pieces into a smooth continuous shape or you can have a series of step backs with the pieces. There’s no right or wrong.
I do caution against excessive thinning over an excessive length. The lower end of the shaft does add strength and stiffness to the blade. Removing too much of the wood from the shaft strips will effectively allow more flex in the blade. Fiberglassing both sides of the blade does wonders for the overall stiffness, nonetheless I am still aware of leaving enough wood on each strip that it contributes to the blade stiffness.
This is one reason I opt to continue packaging enough wood for two paddles in each kit. Unless you have done it before, it is very hard to know what you like in a paddle until you have made the first one. The making of the first vastly informs the second. Likewise, using the first one will also inform you of likes and dislikes which can then be used on the second.