over the last 5 decades i've seen lotsa variances in what folks consider "bow length" or even "AMO bow length". i measure an unbraced bow from backside nock groove to nock groove, following the lie of the riser and limbs. though none of that really matters all that much. what does matter is if the bow length works well for your shooting style, and it's length allows it to be hunted well. i never met a bow that ascribed to any string length formula - they're all diff'rent, to diff'rent degrees. i build a string for a specific longbow based on what is the bow's best performing brace height, which is typically on the low side. to each their own, and if it works well, don't change a thing.