In history it was more a political thing than a pure gesture of achievement.

If we went by history, then all you'd need for a triumph is for your general to be Consul with a high degree of influence (a given for EB consuls) and win a battle against someone.

Getting a triumph in EB is a mission on the level of returning Alexander's body to Macedonia- something to work for.

I got my first triumph on my first 1.0 campaign, after trying several times with previous versions (I'm told it may have been broken before 1.0 but that didn't stop me trying, just in case) and I was very proud of Aurelius Cotta.