How would we do 2 pop whips?
We only have one major food tile here.
Assuming your capital is at happy cap by the time you have 6 Dog Soldiers, you could certainly whip it a couple of times near the end of your rush building, with an extra chop that would be another 4 Dog Soldiers.
I don't at all think that is a worst case scenario--put his capital on a hill with 3 archers and have him whip another and 10 is not necessarily a favorite.
Anyway we really don't know the layout of the land--there could easily be another AI (or more). Darius could be as far as 13 away.
I agree that if Darius happens to have 3 Archers fortified on a hill in his capital, then the rush becomes risky, or if he has Immortals things could get very nasty. If Darius is 13 squares away, he might not cramp us too much anyway.
I don't think it is necessarily too late to rush him, if its still only turn 23, but the value really depends on the scenario imho. If you are happy with the terrain exposed to the east, then there probably isn't much value in rushing him. If the terrain we clearly have there is inadequate to form an empire, then it may help if we expand towards Darius very quickly. If we can do this peacefully then that's great. My main fear is that Darius will begin by expanding towards us, and as we know, at Immortal level the AI gets 3 cities online very quickly. If he takes all the best spots for himself before we can get a settler out, then perhaps an early war would be worth the risk?
Of course there is always some risk with a rush, but it might help if we know where Darius is, and to which direction he is expanding. I notice a pig resource and a river to the west, if Darius doesn't get there first, perhaps there could be some good city sites for us? That is assuming that Darius is located west. It will be interesting to see what is hidden by the fog SW too.
BTW, bear in mind that Immortal level is currently very challenging for me. Although I can beat it, I would hardly say that it's in my comfort zone. You are very likely the more experienced player at this level, so this could be a case of the amateur preaching to the pro.
Anyway, I'm sure I'll find this thread educational, so good luck!