In my current 4-Hotseat/Quick/Inland Sea game I first sneaked Babylon's Wukong behind Byzantium's front line and razed an unwalled city, though Wukong didn't manage to escape. I was trying my best to recover with Byzantium but it was trailing hard behind the other 3 Civs... but then I managed to get Arthur for Byzantium.
So I grabbed 4 scouts and a couple of Horseman and marched on Babylon. It was glorious! The Scouts-turned-Questing Knights cut through one of Babylon's cities like butter and razed it to the ground. It was payback time! They kept pillaging and pushing onward and it seemed it was possible to raze a second, crucial city, which would likely have meant game over for Babylon... but I got greedy and overstretched a bit.
On Babylon's turn a single Babylon Knight comes unexpectedly from the rear and kills one of the Questing Knights, while an archer makes a tiny bit of damage to Arthur, enough for him to be brought down by two Spearmen units trying miserably to hold the line. In the same turn Babylon also finished the Statue of Zeus.
This means that in a single turn Babylon unlocked Machinery, Military Tactics and Military Science... so Pikeman, Crossbowman and Cavalry are now available to them. They'll want to press their Cavalry tech advantage while they have it. On the other hand Byzantium's high Faith yield means they can recall Heroes with ease, so it will be interesting to see how the situation develops.
---
Meanwhile to the East the Gauls sit comfortably in the lead. Nobody dares get near their impenetrable lands. Their high production has made them leaders in the construction of Wonders, with Babylon in second. Crucially, the Gauls built Apadana, which they've used to control city-states to their advantage, including stealing Mexico City from Babylon, right on their border. Babylon relied on Mexico City for Gypsum and Diamonds. With that shift, they have to make do with a single copy of Honey, since neither Byzantium or Gran Colombia will trade with them.
However, the Gauls are 30 Era Points short and are about to hit a Renaissance Dark Age. It will be interesting to see how they handle it. (Dramatic Ages on)
They have yet to meet Byzantium.
---
To the South stands Gran Colombia. They are protected on their left side by an impenetrable mountain range and forests. Such landscape means it would be nothing but a waste of time for Byzantium and Gran Colombia to attempt to engage in conflict with each other at this stage. After a short early period of war which resulted in each Civ murdering the other Civ's scout, they have remained at peace and neutral.
Gran Colombia is well in advance of others in naval tech and infrastructure, and are about to recruit Sinbad, which will go a long way in helping them dominate the seas. Their natural enemy are the Gauls to the East. The open plains work to Colombia's movement advantage, but so far the opportunity hasn't been there. The next step is to raze Gaul's Allied City-States since they can't hope to compete with them on Envoys.
Gran Colombia could have used their navy to help Byzantium raze a second Babylon city, but doing so would have changed the balance of power in the north too much in Byzantium's favour. Byzantium cannot be allowed to become a threat. As long as both Byzantium and Babylon are busy with each other, Gran Colombia can focus on the Gallic menace to the East.
---
So that's how it's been going for me