Tacitus, I take it, definitely assigns the rank of 'chief' to his chosen youths. They do not at once take a prominent position, but are attached to the rest of the chiefs, who are of firmer age and better tried, and they are not in the least ashamed to be their 'companions'. He then goes on to use 'chief' in a restricted sense, as the head of companions. If this is right, the youths were 'principes' in contrast to the general mass of the population, but 'comites' to their own 'chief' ('princeps' in the narrower sense). The alternative rendering, 'secure the approval of a chief', is barely possible Latin. It also makes nonsense of 'ceteris' following.