There is a freight company in Belgium that has many 20 ish year olds flying the A300. Some start with as few hours as 180 total time and the A300 is their first non-training aircraft type. As you would expect there are some who are very switched on and with it, others who take a bit longer.
There are many who upgrade well before most North American companies would start to look at them for F/O positions!
It is simply a case of being in the right place at the right time, plus possibly having a training captain at airline running the flight school.