@Doomer
You missed the part he just completely crushed the Adventurer's sense of scale with his divine power homie, and the Adventurer himself was all like, "I completely fucked that up."
And anyways, the position of being the Head of the Adventurer's Division is more of a responsibility than a reward, like all other positions of Leadership, and it requires more than just strength. It was mentioned at the end of the last chapter and the beginning of this one that he was the most suited for the position of Head of Division, so it's not only strength they were looking at, especially since he himself led a Clan of Adventurers who all signed up to Crown the moment his office was announced. This implies that he has some leadership skills and won the loyalty of his Clan to the point that they would follow him to sign up with an unheard of organization.
Basically, he misread our MC, got slammed by the MC for it, and then clearly admitted his fault before getting quite the hectic job. Chances are that the paperwork and everything was already done and the meeting with Tower Master was just a formality, especially since Kosuke very clearly established that he does not want to be hands on with the organization, as he'd rather look over it from a distance.
One last thing, you forget that Kosuke has a habit of letting people give themselves just enough rope to hang themselves when they try to insult or push him around. Even the Elven Caretaker of the World Tree was dismissive of Kosuke and the dude just shrugged him off to go on performing miracle after miracle until the Elf had no choice but to acknowledge him, likewise our favourite vampire, who like the elf was dismissive until she had a drop of his blood, and don't get me started on the High Priestess or the Temple she oversees...
This guy was just another person who was humbled by Kosuke, only this time he didn't waste any time and handled it personally to establish the pecking order.
