It can be done for sure in 70 years with the exploit, maybe earlier with insane micro. WE effect on happiness is really negligible if you can have 100 perma stab, and unlocking the whole tree makes everything far easier, especially Imperial Challenge. That side of the oratory tree is actually one of the worst trees in the game, and you have to sacrifice a lot of other good things to get it quick.
I did an Antigonid run for the corners of the world achievement (did WC in 1.4) and I got all of Egypt, Makedon and Seleukid by 470-471, just with the Legacy of Alexander Wargoal, and I did not find the exploit until a couple of years later, but I think you could have access to it earlier. The option to abuse No CB wars makes everything easier, as the northwestern part of the map is actually a chore in WCs because of diplo range issues. With some practice I'm sure it's doable, but that's one hell of a practice. Good luck!