In my experience unless you have Marble in the capitial or 3rd ring then it;s unlikely that it helps with the oracle build.
I like the idea of blocking, but can we afford the hit in terms of research, IW is a long way off, and can we defend that city from barbs with only warriors? Let alone hold it against Shaka? It's basically a dead city without chopping the jungle. Unimproved cows can only take us so far. Cultural pressure from the capital may also play a part, although CRE helps us in this case, Shaka has a 60 turn headstart on equal culture per turn.
I've checked the save @turn 44 and personally i'd be axe rushing Shaka. (This comes from a Builder) We may only take his capitial before having to take peace, but i'd much prefer to have to block/defend the capital rather than the site 1W of the rice. If we axe rush we will lose the oracal and it may be very hard to get it back, but in the meantime what trouble could Shaka cause us? Bear in mind the majority of our land is usless till IW.
I see 2 decent citys, Cap and Pigs. I don't rate the marble city, early game hammers = power. I have doubts about even settling it early.
If we must settle a 2nd site then it should be the Pigs, i guess most of the team would insist on a 2nd city before even comptemplating a Rush. Connect Gold and Copper, build a settler and warrior for the pigs (if we must)
chop the plains, mine. Work them, then at 6 population;
17 Hammers - Axeman every 2 turns
13 Food = 1 surplus
note: 7 turns till whip unhappiness finishes
Change immeadlity to a Barracks, the 20 hammers from the plains chop, 20 more from a forest = 40/50 barrack hammers overlow to Axe. 1 axe per 2 turns.
Roughly;
10 turns = barracks and 1 axe
20 turns = barracks and 6 axe
26 turns = barracks and 9 axes
39 turns = 9 CR1 axes outside Shakas Capital, within the 13 movement turns we could have built the pigs city and have 1/2 a settler and a galley standing by for transportation to the marble site.
Advantages of rush.
Our land is limited for an early REX - jungle,
we will have only the capital with good hammer production - we could build 2 cities that can work 2 mines each = 6/7 hammers per turn, with forest maybe 9 hamm/turn max barely adquate in my view.
Neighbour of Shaka - unpredictable, he will DoW, the later on in the game he does, the longer it takes to gain peace the more disadvantge we suffer.
We gain a capital site.
More land to settle & easier access past the choke point. - Worst case we can settle the area south of his capital without issues
Potenial to conquer more cities
Disavantages
We lose the oracle - possiblly a religion and quick access to courthouse.
It could go wrong and we are setback a thousand years.
If we only take the capital and shaka lives, he will hate us for a long time.
Summary
We have lost S/H and GW unless we chop them both asap, if we lose the Oracle then potenially we have 2 AIs to invade. The land we have is not good enough, both in terms of the terrain and the amount. At some point we will need to invade Shaka, (on this point i think we can all agree). Our available land is just too small and production poor. Shaka will spam units quickly, the later we leave it the harder it will become. If we are planning to build the majority of wonders ourselves we need a second production city. The only decent production city I see is Pigs coupled with Maori Statues, Shakas captial would be a huge boost to our early empire, riverside grassland and minimum 3 hills, it would make a fine 2nd production city even before Leeves and watermills. As it stands there are no calender resources nearby, but i bet there are some in Shakas territory.
If you have copper in your BFC and a nearby dangerous neighbour what do you do in your offline games?