Comparisons of casualties at Ulundi to Rorkes Drift

I refer to the Wikipedia historical article below in regard to the Zulu casualties at Ulundi compared to the casualties at Rorkes Drift.
It is said that the the Zulus lost over 400 men plus uncountable wounded in the Rorkes Drift action against Lt Chard's small contingent of about 140 soldiers.
Whereas it states that in the huge battle of Ulundi when Lord Chelmsford's main army armed with gattling guns and cannon, was suddenly confronted by the whole warrior nation of some 15000 warriors, the Zulus lost only 450 odd killed and 1000 wounded.
Under the circumstances of the action this seems light, particularly as it states that the Zulu army were vanquished forever.

http://en.wikipedia.org/wiki/Battle_of_Ulundi

» Poerty from the Zulu War Rorkes Drift, Ulundi & A Hymn.
» Rorker¨s Drift- scale 1/10
» VC's Rorkes Drift 1879