I use a draw knife on my handles and remove the abrupt shoulder. I did it more to keep the handle narrower than the head to avoid abrasions but I can see the added benefit of spreading out the impact/flex area. I'm also thinking that maybe your dry climate makes the handles more prone split and shatter. Do you treat them with oil such as linseed or teak? In other words dry them down to install and then let the moisture content come back up and keep them oiled to prevent internal grain separation from being too dry.