I believe that Caliban is the most significant character as all the attention is surrounding him (Trinculo, stephano). We also know that Trinculo and Stephano are of a lower status as when they forced him the alcohol and he thought they were gods they immediately took it as a chance to earn money ‘I wahad s the man I’th’moon when time was’ his thoughts when he said this was to provoke Caliban that he was a God who had traveled the moon