Is this real ingame footage ?!!

[Madfish]

Yeah it's real footage and the map size isn't that much of an issue. You could build a map like this even for games like CloD. Using zoning e.g.
And of course it's not realistic - the console market just isn't meant for hardcore simmers...

But still, most of this is procedural and / or bought. The reason why most sim companies don't include such beautiful landscape is not because they couldn't technologically but because it'd add additional costs for the objects they need to buy. They don't just sit there and create models of buildings for years.

So yeah, there is no such thing as an engine limitation responsible for this. Usually it's just money.