Quite correct. For example if you say "A courageous hero charged forward", courageous and heroic are synonyms. However, we use them differently. The same thing likely applies to Toa and other Matoran words.Similar problems arise in Matoran syntax. In the Matoran language, adjectives always follow nouns, such as Mata Nui (Spirit Great), and Metru Nui (City Great). However, Nui Rama and Nui Jaga don't follow this rule. If they did their names would be Rama Nui and Jaga Nui.