I hear alot of quotes or suggestions on bow length for sinew bows,, in my experience it needs to be somewhat relative to the draw the bow is designed for,, not sure one size fits all, I shoot mine through a chrono graph,, and find the length relative to draw can vary, depending on amount of sinew and reflex, and still perform well,, thoughts???
also I find the longer bows a bit more forgiving to shoot,, for example I have some like 48 inches shooting a 23 or 24 inch arrow, and with practice shoot reasonably well, but a 54 inch or longer bow drawn to 26 or 27 is a bit more accurate for me,, I have been making a 62 inch sinew bow for a friend, which most might think is too long for a sinew bow,, but he draws 30 inches, and shooting through the chrono,, shows it perfroms well,, a good hunting bow,, I love making sinew bows,, and they always seem so quite and smooth to shoot,, there is something really different about the feel,,