Interestingly, I haven't found that to be the case, they are hand made afterall....
...aside from the obvious squared ends of the jigged bone, sawcut bone and polished stag - all of my jacks have the same taper from bolster to bare end and the barlows a similar thickness at the bare end pin. The linen micarta, smooth yellow bone, A.blackwood and snake wood all have more rounded handles than my bocote in varying degrees. However, I think that due to the clear grain figuring of the bocote there is more of an appearance of depth than the others.
It is also of note that (in my collection at any rate) the 2015 runs were slimmer than previous years with the exception of the all steel 2013 run which appeared about the same.