Maybe it's just me, but I find the shape of the Glenmont to be very similar to that of the Hudson, and the Herald's shape is similar to the Nouveau Premiere's. The exact dimensions may be different (I haven't compared them), but there does appear to be some likenesses.
Is it just me or is Brian saving his best designs for the production pens? This and the Hudson (especially the Hudson) are sublime.
The Hudson and Glenmont barrels are pretty similar by accident. My hand just made the barrel that my eye wanted to see, and they turned out to be pretty similar barrels! However, the section on the Hudson is the same design that I use on the Glenmont. So both pens will feel similar in the hand. But the caps are different lengths and dimensions.
The Herald and Premiere are both torpedo shaped, true, but the overall diameter is significantly smaller with the Premiere regarding all parts. The Premiere barrel is longer. The Premiere Cap has a taper on the lip, and is thinner. And overall, the Premiere shape is a little "pointier".