Well if you haven't noticed today's games have pretty shitty grass,trees,etc...PC games included
Some games even use 2 poly trees.
As for textures,i would be more concerned about texture filtering,because this is a semi-open world game.
As for painting i was just semi-joking,but some details on Spartans look like somebody painted them by hand literally.
Not much to see in the above shot,that is cropped from higher res image.