Preturn:
I don't really agree that turning off growth in size 12 cities. Let them keep growing and then build a worker when they get close to max. It costs us a single turn to build the worker and a turn (or two) at size 11. Also if size 11 and size 12 make a units at the same speed you can just pop off the worker as soon as you hit size 12.
The only case where size 12 only applies is when zero growth (and nothing else) gives the unit a turn faster. In this case its cities that make 40, 27, 20, 16, shields exactly.
I also think self research will be useful. A good science rate and scientist farms can get us ahead of the AI in tech (especially if we keep cities) to allow us to get to 100% tech rate and still have positive gold.
860 AD: Build the new town of Rock Lobster as NP mentioned. Use 14 hp Army and 3 Llama-ro's to capture the city.
Armies heal for the most part.
Pick up Economics for Magnetism.
I could trade away Mil Trad and Economics + gold for Democracy. Democracy being a govt tech would be worth a lot more for buying TOG, but since Mil Trad is not well known, I decide to skip the trade for now.
IBT: Single Knight charges us.
870 AD: Kill several Muskets in Buenos Ares. Jujuy is now empty so a flip won't hurt us. We also move toward Mendoza.
IBT AD: Advancing Knight Knight landing and a Longbow.
880 AD: Capture Mendoza and Buenos Aires.
No good trades. We really want Indonesia to pick up TOG as we have 4 techs they do not for trade.
890 AD: I can cover Mendoza but not Buenus Aries. It has a single (regular) Musket Guard since I didn't adance last turn. They may take it back in which case it shrinks a bit. Armies are healing next to Buenos Aires so getting it back will be trivial. We should also capture the next city in line so it will be safe after this.
IBT: Well this is excellent luck for us...Aztec and Sioux are at war.
Argentina and Aztecs are at peace.
Oh and Russia and Indonesia declares war on the Aztecs
Argentina did not in fact have enough units to take back Buenos aries. I think it wasn't attacked.
900 AD: Rosario is captured. It was closer than I thought it would be as one army took big damage vs a Musket (9 hp of 14) One injured Knight kills two of our units an Elite Mace and Vet Llanero
IBT: More dogpile on the Aztecs by civs that don't matter.
910 AD:
Capturing San Juan goes very well and our Cavalry Army kills 3 Muskets. This was nice as it was the only Army that could reach.
920 AD:Bahia Blanca capture by Armies. Attack La Plata with Llanero and capture the city without loss. Defense has been lighter with 2-3 units and occasional Regular.
Finally got a leader and build a new Army
Note that I have been checking deals but no civ has gotten TOG before any other tech.
930 AD: All our Armies need to heal. If Argentina builds or has a Knight they can take back La Plata but we have troops near it.
IBT: Get our first flip of the round with Buenos Aires.
940 AD: After bombardment a MDI takes back the city and becomes elite.
For Santiago del Estero we first kill Muskets with Armies but also find two Spear (we took their saltpeter) which is attacked by Elites that both win.
Some slower units are already marching back.
I build Bilaboat which builds a Galleon for our 3 uni army to ride.
950 AD: I may have missed recording what happened for this turn, but we own the continent and stuff is healing or moving north. We still have to deal with flips so some armies should stay south.
Notes:
The active unit is the size 3 army. I would put it into La Plata next turn. The turn after the army can be loaded while in the town, and dropped off on the island with no risk to the Army. La Plata flip during that one turn would delay us and cost us the boat. There is a settler that could replace it but its not far enough south.
Units (especially slower ones) started north but it's long trek. Several armies are Healing and watching for flips so they can take the city back.
Tech is still not happening. Either Germany or Indonesia could get TOG and we have 2 tech to trade for it. My thought is maybe to try to
steal from the Aztec when we are ready for war. If successful, we have the new tech. If fail they may declare war on us giving us the war happiness. If we fail and they don't know about it, then we can choose to war or try again. I am unsure what is the best choice when you want to go to war. It might be to try immediate perhaps more than once.
We can also just trade without getting a 2-fer for it.