If you're using mace, I suggest using it in tandem with nutmeg for a rounder flavor. I'd probably use cardamom or clove instead of allspice, which can be more like black pepper than anything else. Clove and nutmeg are more intense than the other spices, so you'll need less of them.
I don't bother with stressing over adding measured amounts when using spices for a beer. Instead, I simmer a spice tea with water and whole/cracked spices until I like the flavor and pitch that at flameout, until I once again like the flavor. Some more could be added prior to bottling if you feel it needs it.
The moral of the story is that it's better to taste, adjust, and see vs. asking if there are proven additions that work. This advice won't help everyone in every situation.