For handle scales I like the JB Weld products. The 24 hour cure version when clamped has, so far never failed me. Excess glue in unwanted areas cleans up with acetone before it sets. If a scale slips when clamping, you have plenty of time to reset and reclamp it. The JB Kwik sets like its name says, so be aware of that. After 24 hours, you'd need a jackhammer and C4 to remove the scale. It does grind well, and can even be machined, though that is not in view here. Though I haven't tried it, I've heard that Gorilla Glue "impact tough" c/a glue is not as brittle as the regular stuff when dry.
In the old Neo-Tribal days, for stick tangs in deer leg bone handles, we used to use a Native American glue, which was melted pine pitch, a little beeswax, and something added as an aggregate. Crushed up (old) brick dust worked in the mix, as did wood ashes. Some of our NT brethren even used dried moose dung, as it was more fibrous than other dungs, so I was told. I never doubted moose dung's efficacy, but being that I heated my home with wood, I had an abundance of ashes, so I never took much interest in foraging around for animal droppings as an aggregate. I worried just a little at how a customer might feel about having manure as part of the raw materials, but whatever floats your boat.
Two things about the pine pitch glue, it sets up quickly and holds well, so when pouring it into the hollow bone and inserting the stick tang, work quickly. It helps to warm the tang with a torch too just a little. The other thing is never never never never never get the hot pitch glue on your skin. It's very hot when liquid, and it sticks like super glue to skin. It has to be removed with a knife, along with the affected layer of skin. You WILL have instant empathy for folks back in the day who were unlucky enough to have been tarred and feathered. Just sayin'....