Whilst the tradition of the Doctor having three companions had been established from the early days of Ian and Barbara travelling alongside first Susan and subsequently Vicki before settling into the one boy, one girl pattern for the remainder of the Hartnell era, the arrival of Jamie briefly brings the number of companions up to three and, for the only time in the series history, two of them are young men.
I've often thought of season 19's tempestuous trio of companions combined with a youthful Doctor as turning the TARDIS into a time travelling YMCA but how do we think this earlier trio of young companions and their newly rejuvenated impish Doctor compare?