Lord Parkin
aka emperor
Probably overall, yes. But the time it takes to win each war is considerably less, because there is less land you need to take to eliminate a nation. And of course, with factors like war weariness making drawn-out wars very costly, shorter wars have considerable advantages.Really? Do you mean that the two continents are in competition with one another or a free for all. Because in a free for all, I would expect that the time that it takes to conquer the crowded continent is somewhat higher.

Of course - you will likely get a few smaller groups that share research between themselves. But this is still more advantageous than a continent with 2-3 people, because you have no guarantee that any one person will be someone you can easily work with. With 15 people, you can choose your allies much more easily.Not really a competition there, the crowded one has a big advantage. Although 15 civilisations cannot perfectly cooperate in research as there are not 15 parallel tech paths. (I'm assuming no teams here.)

Indeed, too much land is not a bonus if there aren't enough civs to utilise it in the early game.I also guess that all of this depends a bit on the room for expansion. If the 15 civilisations can expand decently, then the 3 will have too much room which cannot be used in the early game. This is likely to be true in the America vs Euroasia example, so therefore the American continent will have a slower start.
I wouldn't say that hammers and research points aren't all that important - they definitely are. But trading groups and alliances are also important factors to consider, alongside land and power.Of course what I meant with Land = Power is that eventually the size of your land largely determines the amount of research points and hammers that your civilisation generates. That hammers and research points aren't all that is important is however also true.

Yeah, that's pretty typical in my single player games with the AI as well. 2-3 civs isolated on a land mass will tend to become considerably backward compared to the rest of the world as the game progresses. (And of course, this is even more pronounced when it's just 1 civ isolated by themselves.)When I have found 2 AIs on a land mass for instance they are too backwards to be a problem. Their longbowmen don't hold up well to my riflemenThat's pretty typical with few exceptions.