I was always taught that cracked wood should be glued up as is. Stop hole drilled at end of crack to prevent further propagation. The idea is that the cracked wood gives a lot more surface area for the glue to work on. And a tighter fitting glue joint is stronger than a 'wider' joint that depends on the strength of the glue.

I have glued back together several broken gun stocks this way and they have all survived in tact. Well, except one. When the owner broke it again it broke in a different spot. I think he would get mad when he missed a bird and swing the shotgun against a tree.