t would need to be shortened about 1", which makes me question whether it is worth shortening at all.
In Maggie Righetti's book 'Sweater Design in Plain English' she adds 1" to the sleeve length measurement to account for the elbow bending action so your sleeves sound as tho they might be about right. From your initial post I was thinking you were talking 'down over the hand' kind of extra length.
If you can get your hands on a copy of Righetti's book, it's a great resource, esp as to understanding the properties of knit fabric. From my exp, making a sleeve a length that looks good when first tried on, means in no time it'll be too short as the fabric stretches, pulls, etc from movement.
ETA: If you're not already familiar with Jared, check out his blog at brooklyntweed.blogspot.com and his sweater designs. Lots of fab pics of his work that might help you gauge the sleeve lengths he does on his pieces.