Golden Age Arco does seem a bit rough. If memory serves, Sloth is mandatory (not unreasonable for a philosopher-dominated society

), but your myrmidon heavy infantry, while very nicely equipped, require substantial resources; and your icarids are fairly expensive for their fragility.
With that sort of setup, a few things come to mind. Bear in mind the caveat that I haven't poked at this theme much at all...
Hire mercenaries. This would might be less cost-effective in an MP game if there's a bidding war. Your initial bottleneck for getting an early army is resources, not gold, so this seems like a good choice. Heavy horsemen, heavy infantry (including the Ship Wreckers), the pike formations (God's Justice, perhaps others) come to mind. You have no archers, if memory serves, just slingers, so Farstrikers would fill a gap but you would still need some infantry as a screen. Farstrikers can be useful against lightly-armored folks like barbarians, but likely won't do much against heavy cav. Chariots can also work well against lightly-armored.
Consider aiming for Riches from Beneath. It's an Earth enchantment that will significantly boost your resource production and thus troop production if you have the gold to match. Later on you'll probably be able to supplement your human troops with living statues and mechanical men, and a couple of your heroes make superb heavy infantry (Pathos the Son of Titans comes to mind as somebody that shine with good equipment, and the Asterios Monster in the Maze is another candidate for better gear).
If you go heavy inf/chariots, I'd probably put the heavy infantry pretty far back and center, on hold/attack, and chariots massed on one flank and even further back, on hold/attack archers or rear. Any light infantry should be put closer to the front to attract missile fire. And don't forget to bring along Priestesses for the after-battle healing. Later on mystics may provide good fire support, but you may not have researched enough yet. *shrug*
The one pain I remember from my Last go with it was the irritation that, according to Acashic Record, my highest magical income was in Death, and Arco/GE is weak in death and blood magic until you boost a Priestess and start summoning Lamia Queens.