There needs to be some damage or good fights taken along with sacred sites secured. Maybe you can find the castle timing before the Byzantines age up themselves, take most of the relics, get started early on those upgrades which are slower for Delhi. Maybe even find a timing with elephants, men-at-arms and archers, or lancers.

But as Delhi, you can't just go castle age and spam War Elephants against a civilization like the Byzantines. They have some of the best spearmen in the game with Limitanei.

Especially in this matchup, you can really reason going for an archery range early on instead of the stable play, just because the Limitanei are such a key part of the Byzantine army. You will pretty much never get any value with just immediate Ghazi Raider play.

If Delhi can get the sacred sites early, they can match the olive oil income that Byzantines will end up having.

One thing where I do see Delhi as a little bit favored is in a long drawn out feudal game towards the mid end is where Delhi suddenly starts getting Pro Scouts in for free and just starts shoveling all of the deer underneath their TC.