Ah yes, let's test the competency of the new guy with attempted murder. Bad enough the proctor seems to be an overly aggressive battle junky, but conducting the test without even determining if the chap wants to apply for the new position is just utterly asinine.
Yes, yes, you can take your manga logic excuses and feed it to the well meaning poisonous cook of your choice, but that doesn't change the fact that the tested individual even wants to join this club of battle maniacs. And that doesn't even touch on the fact that the person they are testing has unknown intentions, morality, and temperament. Sure being thrown into that last mission would give them some idea, but a month or three isn't enough time to get to know a guy, let alone determine if they are a fit for what is essentially the cleaners and troubleshooters of the government.
It's one of the reasons I hate that concepts like manga logic exists. It prejudices the audience into ignoring inconsistencies, horrible logic, and all-round stupid thought patterns. It has also functionally poisoned the thinking of a generation or three of their readers.