i struggled as Armenia, experienced something very similar to what Follow described... at the end just grown tired of a stone age and countless Seleucid stacks, and their new family members who tend to attack with all mercenary armies. what i'd suggest is to definitely try money script or play on H campaign.
VH is a bit too overwhelming, and even H difficulty dont stop them from hiring full stacks of mercenaries, but does however tone them down a bit.
also there is a problem with Hayasdan in current build: cataphracts aren't available and afaik elite spearmen's status isnt right.
waiting for a next build to start over their never-ending struggle