If by assassin you mean the martial artist, I would agree on your idea of focusing on accuracy instead of evasion.
This is because in late game, the only reliable defense mechanics is BLOCK, which has 50% chance of nullifying 100% of the incoming attack, if you max BLOCK. Which is easy to do with trophies, blue shield, certs, and the natural high strength of the martial artist. For melee dps, it's all about survival in late game.