Accepting your interpretation puts the paragraph even more in need of deletion. It says that the Gaelic taoiseach could be translated as chieftain in English, true, though very worded as true word 'equivalents' do not exist, but why does it say that? Either the suggestion is that the name originally envisioned was 'taoiseach', which the band then translated (if this is the case, where is the source), or it is irrelevant, like writing in an article about The Rolling Stones what there name might be translated as in Gaelic.