There’s a very practical reason that novices should not assume leadership responsibility in the Church: pride will destroy them-
A bishop then must be blameless, the husband of one wife, temperate, sober-minded, of good behavior, hospitable, able to teach; not given to wine, not violent, not greedy for money, but gentle, not quarrelsome, not covetous; one who rules his own house well, having his children in submission with all reverence (for if a man does not know how to rule his own house, how will he take care of the church of God?); not a novice, lest being puffed up with pride he fall into the same condemnation as the devil. Moreover he must have a good testimony among those who are outside, lest he fall into reproach and the snare of the devil. (1 Tim. 3:2-7)
Novices, like the Devil, are too often the victims of their own prideful folly. Spare them, and keep them out of positions of leadership. Let them grow before you heap responsibilities on them.