All of them, the dinka and the nuer shares almost 90% of the dialect, told you to think of Xhosa/Zulu in RSA.

The British have sent a second flight to evacuate their nationals from Juba. The Americans have also gone in to get their people out. And now this: Riek Machar has demanded that for there to be talks, Kiir MUST step down as president and elections fast-tracked. Kiir's invitation of the UPDF (the current contingent is, I see, two transport planes and more than 300 soldiers and equipment) is more to secure Juba's government facilities than anything else.
Since this is now a full conflict, we can analyse the relative strengths of the two sides quite comfortably.
Kiir will have the support of China and the US, as well as of Sudan and now Uganda. The superpowers want the oil to keep flowing, as does Khartoum, whose livelihood is based on taxing Juba's oil transit shipments. Kiir is in office quite legally, and even in politics incumbency is vital. Widening the civil war in order to topple Kiir would create a refugee crisis at just the same time that Kenya is overwhelmed by refugees from other countries in the vicinity - and those SS refugees would of course come to Kenya.
The balance of international actors, therefore, are likely to urge Machar to cease his rebellion and await the 2015 elections!!!

Do the Nuer leave in areas fertile with oil fields?

If i were Kirr's advicers i would ensure i first secure Juba and life goes on near normal.. then i would marshal support from US and maybe China.. getting Uganda's support is crucial.. talk in Kenya

I would then avoid this tribal targeting.. ati Nuer's are being fought by Dinka's i would actually encourage those doing business in Juba and elsewhere to continue..

I would then appoint another renown Nuer into government.. a top Civilian with no military background. not those military generals.

Riek would be isolated and things would calm down.

I would love to hear a contra opinion based on matters on the ground

And to add on that, and not to sound bias, I'm wondering why, it's just recently. Are South Sudan betraying their habit of complaining? Does that tell us something about them? Maybe they have some inherent problem.