After a lengthy amount of experimentation, it seems that if you want a good chance for a more subtle game, TSL, you have to play without Aztecs, Scythia, Sumeria, Kongo.
Those four are repeatably guilty of disturbing the peace - wiping out other civs. I suspect Gorgo is the same, but only played with her once.
Without those four, world is much more sane, and someone conquering France is the only civ death with a decent chance of occuring until gunpowder.
Since patch, I'm seeing less settling (no barbs).
Australia might be OP for a player, but not impressive as AI. AI Kongo is still PE1.
I've seen Poland struggle, but I've also seen them wage war successfully against both Russia and Scythia at the same time and do well. In my current German game, Poland has both their capitals. Scythia is alive, Russia is dead. Germany is seething (Cleo died too).
Regarding map playability... all seems good. I might suggest an option to make polar cap sea tiles coast, so colonization can happen sooner if one so desires. I might also buff up Hawaii and some of the pacific 1 tile islands... make them 2 or 3 hex, or put them in tighter groupings.... except for a naval base, there is not much value in them.
Funny how in III the ai settled everywhere. I really miss the settler races and a nice full map.
edit 2: its just silly to have a world map 2/3 empty in nuclear age.
I agree with some of your observations, but a lot depends on what scale
you play.
I only play GEM ludicrous size (230x115) at marathon pace; 20 civs 30 city states.
I have found that Congo and Brazil are by far the most difficult to beat.
You have to confront them early, or at least stifle their growth.
One way is to build near them, e.g. Madagascar or Panama, which helps to
stop their expansion a bit. Madagascar usually has one or two luxuries
that are very useful. Another way is to trade with their neighbours to
give them, for example, iron, nitre, and other goods that will help them
from being overwhelmed.
Aztecs can be very strong, but again, it's worth starting a city somewhere
in the north of America to help stop their dominance.
Rome is a real nuisance, and can be very strong. I rank them as the toughest
of the European civs.
Sumeria rarely lasts long - Arabia, Egypt or Congo often take them out early.
India is always a pain, especially when they start expanding.
Scythia have never been a threat. They expand a lot, but don't quite finish
the job enough to win.
France, Russia, and England hang on without ever looking like winners.
Gorgo, Pericles and, to a lesser extent, Germany, don't often last the whole
game.
Harald piddles around Norway without ever looking like a worry.
Jadwiga does a good job early, then goes insane in the Mediaval Era and starts
speaking Portugeuse. (The end is never far away when somebody starts doing that.)
Spain often takes over huge parts of North Africa, which is a good counter
to Congo, and should be encouraged. Spain have never done much late in my games.
China are a problem if not confronted early; same with Japan.
Australia are fun to play if you like developing a good base of cities without
worrying about pesky neighbours early in the game. Watch out for Japan who will
attack when they find you, if China isn't giving them trouble at home.
I've been attacked in Australia after Japan managed to sneak troops down through
New Guinea without me noticing them. Very nicely played, I thought!
I think the AI does very well at the scale I play. I have never been been beaten
and thought that I had been cheated out of a victory.
