Lego originally derived most of the Matoran names and some of the Toa names from the language of Maori. For example, Tahu means a veriaty of things in Maori, but one use for it is Flame. And Nui means great, hence Mata Nui, and various Rahi Nui combiners. The Maori thought that Lego was benefieting from their culture and heritiage, and threated a lawsuit. Thus, Lego had to drop some of their names, the most noteably being Tohunga changed to Matoran. Also, Lego changed the spellings of some Matoran's names, like Jala to Jaller and so forth. That should explain.