Agricultural is universally acknowledged to be a requirement for a top game. That's because food leads to every other output, be it production, commerce, or expansion. Mostly expansion, which then further enhances production and commerce. This trait allows an extra food for cities on fresh water in despotism, and an extra food in all cities after government transition. In addition aqueducts cost 50 shields instead of 100. this allows you to grow much faster throughout the game, both wide and tall.
The second trait is less certain, but generally religious is slightly preferred over science. The truth is that you can do great with both, but the reasons and tradeoffs are complex. See here for a more complete breakdown:
https://forums.civfanatics.com/threads/spoonwoods-hall-of-fame-attempts.296795/page-11#post-14646211
Personally I'm going with the Sumerian's (scientific) for this gauntlet because they give more SGL's, which gives me more map options to choose from for the same number of maps played. But this is putting a really fine point on it. I played the Celts as well for a while and if I wasn't SGL fishing 3 cow maps would probably be playing them still. Both are extremely good choices.
The general strategy is:
Get as much land as possible while building the Temple of Artemis in one of your second or third level towns.
Get to Feudalism quickly and then keep making settlers.
Expand until you hit the domination limit or other civs. Consider war if necessary.
Then build every town possible in all the corners of your empire. This gives you a temple in a ton of towns from the ToA.
Finally whip libraries and cathedrals, and don't research education which would make the ToA obsolete. Keep producing culture wherever possible and run out the clock.
If properly executed, this strategy will be far more effective than your second trait selection.
