Re reading some suvivors reports for another topic it starts to look as though there were two Durnford Dongas.
Firstly a stand in the Nyogane Donga around a mile from camp, Barker pin points that, and then a further stand in the Mpofane Donga, around 300 meters from the camp. This the Donga that Bradstreet took up position in. Davies says thats where he met up with Bradstreet and Jacob Molefi seems to point to it as well.
Davies says that when they had made a stand 300 meters from the camp he was in line with the soldiers. This makes so much sence in terms of time and space in that when the line was breached by the Zulu they were then virtually at the camp gates, not still a mile away. Hence the immediacy of the threat to the troops rear.
Just a thought