I agree about willing to share the world for a trustworthy ally which is much more realistic in a common sense manner. There would be an uneasy truce perhaps and a bit of intermarriage but overall nations should see the advantage gained in alliances as it makes them stronger. And I mean real alliances not like the phony baloney ones that rulers would make or break with or without reason. I know its a balance between historical accuracy and gameplay but when you're a nearly unstopable threat people would more likely kiss your ass than try and kick it.