Maybe it's a play style thing?
I tend to keep a strong military (even when I'm in builder mode) that's plenty visible to my neighbors, though I rarely threaten them directly by parking them right on the borders. It usually seems to keep the 'warmongering' type civs fairly friendly but tick off the peaceful ones over time who don't like how rapidly I expand during the early game, especially in their direction.
Or maybe it's just a trick of the randomizer, that makes Greece so friendly to me.
-Elgalad
might be a difficulty thing too. ive noticed him be more rational on king than on prince or warlord but also completely psychotic on emperor. havent played enough deity to know his personality there either.
ive met him on turn 3, denouncement on turn 4, ask for friends on turn 15, dow on turn 18. he's even dow'd me on turn 6 before. i used to be really intimidated by him before i got some early turn experience with it. now it is just fun to see him. i know to keep his trades at arms length and that RAs with him are pretty much a crap shoot. but yeah, might have just been our random experiences and not consistent with his actual game style.