I concur with Terri's point. In custom clothing, you can rotate the sleeve in the scye as a workaround to compensate for a draft that is slightly "off".
In RTW, we would revise the pattern so the underarm seam would be sewn "in one". Not only is it easier, it's also a hallmark of concienscious engineering. Said another way: what you saw is not a hallmark of quality.
It is true that I tend limit the crown height because the flatter sleeve cap sews more easily in RTW production. But, it really depends on the market and pricepoint. Most better-grade apparel (viz. Nordstrom, etc.) have sleeve caps range between 5" and 6" - some a little higher or lower; but, the majority fall within this range.
For personal projects, I tend to like to standardize myself to a 5 1/2" sleeve cap for dress and sportshirts. I find this handles easiest under the needle and I'm happy with fit and style trade-offs.
All that said... I have released sleeve caps as high as 7" into production for several designer-grade labels. This is not a whim, though. The equipment and skill of the operators need to be assessed before doing this.
Edited by jcsprowls, 25 July 2014 - 03:26 AM.