It actually looks like we lost an option from civ2. The land forms are archipelago (islands), pangaea (one super continent) and continents. Civ 2 was arch, cont, and varied.
While you might want pangaea for a Triassic scenario :frog:, all it really does is limit the usefulness of ships.
The varied land form in civ2 was what was supposed to give you something like the earth, with the Africa/Asia/Europe and N/S America as two super continents, Australia as a major island (no offense mates), and the SE Asia and Caribbean archipelagos.
I agree that the civ2 map generator was not ideal, but I usually generated random maps with varied land form, edited the areas that looked wrong, then saved them and played them months later.
It could be that the 60%-80% land coverage was what civ2 actually did with small/medium/large land mass.
The civ3 screenshots I have seen worry me a bit - the maps look a lot like civ2.