Therefore, the task of training new recruits has always been handled by the teams with lower rankings.
And those team leaders who came for the draft were more than willing to do so.
First of all, vanguards in the academy are free to move around, and as a lagging team, it's practically impossible to poach anyone normally; starting with the draft to cultivate rookie potentials is simply the only choice.
Secondly, even though vanguard transfers are free, according to the academy system, teams that recruit a vanguard must pay a considerable "transfer score" to the vanguard's former team, which the academy believes is the only way to maintain a healthy competitive ecosystem, otherwise it would devolve into a malignant situation where the rich get richer and the weak await death.
Lastly, although new recruits start out relatively weak, they have the advantage of being obedient and hardworking, which to any team leader is preferable to a middling but complacent veteran.