Capítulo 1870: Competition And Struggle For Survival.

He believes that not everyone will be able to get a class by the end of the one year training because the F-rank missions are only enough for everyone to do if they do just one. But the reward of a single F-rank mission won't be enough to acquire a class.

Everyone will need to do at least ten F-rank missions without failing a single one if they are to get a class. If they fail, they will owe training points and have to do more to cover that debt.

But if someone does an extra F-rank mission in a bid to gather training points for a class, at least 9 other people else will lose out and have to do the difficult E-rank mission. 

It is without a doubt that many people will be forced to do the E-rank missions. But if they fail to complete the E-rank, they will owe 10 training points. So instead of gaining training points and moving closer to their goal of acquiring a class, they will fall into debt and move farther away from it.