Turn 55
Another slinger is out in Aachen. It starts working on a builder, as I feel safe with the amount of slingers I have now. The builder will be out in 4 turns, and Aachen will grow to size 5 in 5 turns. Checking the production values, Aachen can complete its commercial hub in 9 turns now and its campus in 11 turns now, but those figures should be cut down with the future mining of the grassland hills here.
Cologne, in the meantime, is going to produce a slinger next turn, and it's going to grow to size 5 next turn. It's going to need some builder help and I might decide to buy the two tiles to bring the iron (to the west, near the entrance to my peninsula) inside my borders to mine it. It will cost some gold, though, but given that I have 245 (with 11.5 income) right now, and that 150 will go towards upgrading 5 slingers to archers (not necessarily in one go), I should have enough gold to buy those two tiles in a couple of turns. It's not in a such a rush though, since I don't even have a builder out yet. Food for the future turns. Cologne can complete its commercial hub in 17 turns - desperately in need of more cogs here!
Mainz grew to size 2, picking up the very nice copper hill (1f2p2g -> to be 1f3p2g once mined -> 1f4p2g with apprenticeship). It has a slinger in production to be out in 4 turns, but I won't delay archery anymore for that, so all of the production will transfer to an archer production there.
Here's a view of the center region + northwest of my peninsula. Yuris has 2 eagle warriors moving around here, but I doubt he's going to attack me. I have 2 slingers (soon to be 3) here and my warrior, and the settler finally arrived to the gates of Mainz.
One more turn of research into Masonry, and next turn, I'll finish Archery.
I see no more settler production from other civs (like me), so it looks like that phase of the game is over.
Turn 56
Cologne finishes the final slinger (my 5th so far) and grows to size 5 at the same time. It starts working on the interrupted granary. With the production overflow, it will produce the granary in 1 turn, bringing the much needed 2 housing here (housing is 5/5 now).
Here's a view Cologne. I decide to place the newly grown citizen to work the whales (2f1g) instead of a marsh (3f) here as there's plenty of food here. I would work a hill or forest tile, except there are no inside the borders, so I decide to pick up an extra gold here.
Not much else this turn. The settler moves NW-NW to be NW of the city center of Mainz, and I make sure there are military units of my own between the settler and Yuris' eagle warriors here. No need to tempt the fates by putting an exposed settler out there.
Turn 57
Archery AND Military Tradition are completed. Next on the science side is Horseback Riding (5 turns), and then Apprenticeship (25 turns, but will soon be cut in half as I'm going to have 3 mines definitely by the time I start researching this tech). On the civic side, I choose to research Games And Recreation (12 turns - boost is Construction tech, but I don't think I'll have that researched in time) since it's on the way to Feudalism.
Here's my policies after I use the free policy change that comes with the civic research completion. Agoge is replaced with Conscription, since I'm not building slingers anymore (agoge served its purpose well) and Conscription will cover the maintenance cost of the archers I'm going to have pretty soon. The other change is that I get charismatic leader back (+2 influence points) to get more envoys faster.
Mainz's slinger production turns into an archer production. With Agoge, it said 4 turns, but now that I switched that out, the archer would come out in 6 turns. However, I switch the production to monument (15 turns) since I'll need the culture here for quicker border pops.
Cologne finishes its granary, and the growth to size 6 drops down from 43 turns to a more manageable 8 turns with the increasing housing and the extra 1 food from the granary. I still keep the 5th citizen at the whales since there's plenty of food here as I said before.
You can see Yuris' two eagle warriors moving to my peninsula. The slinger on the truffles tile will be able to move SW next turn to block the eagle warrior from moving further inland if it decides to do so. Also notice that I already upgraded one of the slingers here to an archer (SW of Cologne).
Here's the screenshot for the center. One of the slingers moved to where the new city will be settled since I didn't want Yuris to move his eagle warrior there and block my settler. The settler SE of the first slinger is covered by the warrior, and it will be able to settle down next turn. The second slinger covers the southern side; Yuris' eagle warrior in the south is too far to attack anyway. You can see the third slinger SE of Mainz, too. So, between the new city and Mainz, I'll have a warrior and 3 slingers (soon archers) defending, with another archer in Mainz to be produced in 6 turns (or even faster if I add some more production there) if needed.
Sullla is the first to 9 techs now. Everyone else has 8 techs.
In terms of civics, Sullla is at 9, I'm at 8, Archduke at 7, and Yuris at 10.
Here are the most recent military strength scores for each civ:
Me: 95 (it was 50 before I got 3 slinger out, so we know that each slinger is 15 points, and this will increase more next turn once the game registers my first slinger->archer upgrade).
Sullla: 85
Yuris: 84
Archduke: 80 (He was at 65 3 turns ago, so a slinger out for him, too?)
Given these numbers and the relative lack of increase for the other civs in these past 3 turns, I think I'll be able to defend my cities if needed.