Making EB More Rewarding

[Atraphoenix]

I role play to revive Achaemenids and unification of whole Persia, so I role play with early blitzing that means I use Arsaces in the story line like that;
-he rebels AS,
-He conquers Persia,
-He conquers Mesopotamia,
-before he manages to to revive Achaemenids, he is killed in action, after his loss the kingdom is in a disarray, many cities revolts, feudal lords destroys the unity and abandon the royal court,
- then a young prince comes of age,
- he rebuilds the unity punishes the the traitors and chains them oars (death ships lol )
- he challenges other successor states that claims they are the true claimant to Achaemenids,
- he destroys or make Hayasdan and Pontos his vassal,
- he attacks to Ptolemies, he exiles them to Crene or Nubia,
- then the most funny part; he attacks mainland with more than 300,000 men then I will either make the script a happy end for him or another 300 glory for Greeks..

so to role play with ups and downs is more enjoyable for me. just upper and upper is not so realist or fun.
and I am look forward to wait for Yuezhis but I do not know to make their invasion more aggressive, anyone knows how to make them more aggressive or under which conditions they attack like mad?
because I want to role play to lose my two kings will die on that invasion.