Here's a recounting of my France, Tiny, Pangaea, King game.
Turn 75
7, 2, 2 population.
2 spearmen
2 warriors
2 workers
Completed: Wheel, BronzeWorking, Calendar, Trapping.
Civil Service is 8 turns away.
Stonehenge 7 turns away.
3 Monuments. No other buildings.
Social Policies: Tradition 5/6
Notable randomness: Fountain of Youth +10 happy, so ignoring happy science.
Turn 2: +1 pop from ruins.
Turn 250 (1700 AD)
21, 11, 10 population
2 Pikemen
1 Musketeer
3 Crossbowmen
1 Cannon
2 Caravel
2 Workers
Science: Archaeology, Acoustics, Chemistry.
Fertilizer is 2 turns away.
Wonders: Hermitage, Ironworks, National College, Sistine Chapel, Hagia
Sophia, Kremlin, Louvre, Stonehenge, Colossus, NotreDame, National Treasury
Social Policies: Tradition 6/6, Piety 6/6, Freedom 6/6
Culture 272 + 75 + 42 = 399
7 landmarks.
At this point, Science is mainly for defense and production. I don't really
need any more wonders to win. My next focus is to get a bunch of artillery,
and build any helpful buildings (finish my museums, then happiness due to
piety's conversion, then the rest). I hope to win before bombers become any
kind of threat.
Notable randomness: My incredibly weak military score has caused all 3 AI's
to declare war and send armies (even my ally :( ). Sorted them out, but
situation is still risky. I lost a couple workers, and it's hard to build
improvments with enemy units standing on those tiles. However, cities were
never really at risk.
Turn 350
There are 15 enemy units on my lands, a mix of modern infantry and tanks. I have ~6 artillery trying to sort them out... (note from the future: I wind up losing all military that isn't in a city, but I do enough damage to push them back.)
1.5 policies to go. 14 landmarks.
Turn 370
City pop: 25, 19, 17
All policies done. Starting Utopia project. Currently researching Electronics. Did not research Radio.
Turn 390: 1970 AD
Cultural Victory. Whew.
Additional notes: King is much harder than I remember... by the end of the game, one of the AIs was able to field a ~40 military unit offense. Fortunately, he sent it to another AI. I feel the Fountain of Youth greatly influenced my game - I never hit unhappy and I was able to put off Theater science and buildings for a long long time. I feel I built too many wonders at the start of the game and should have instead built more units.
The AI's took all the city states as allies, I never sent any of them any gold. I never had much spare gold to send them either.
I ran a comparatively idyllic prince game (france, pangaea, tiny). Two city'd my way into a cultural victory on turn 317, 1894 AD.
Best Answer
Micro-Empires don't work for all victories. Almost by definition, you probably won't win a domination victory with a micro-empire. To do so you would need to raze all cities you capture (to stay micro), which would just give your opponents space to expand, which makes your job harder. It would also be difficult to balance advancing your cities and cranking out military units without falling behind on both fronts. I think a minimum of 4 - 6 "core" cities is a must for a domination victory. It may be a great challenge to try it with two though.
Having said that, in addition to @WillfulWizards hints:
to slow the enemy down in your territory as much as possible. Adopt defensive policies.