Few Bishops have the ability to be theologians, so time would not help them.
The training of modern Bishops and priests is very thin compared to past times when a lot of priests would continue their studies for twelve years or more. This produced clerics with theological depth and comprehension which is rare today.
Since the council it is usually four to six years and then off to the altar and the pulpit.
The theology offered in seminaries has been deficient even before Vatican II.
In the past, priests and bishops had more of a spiritual training akin to being in a monastery, with the monastic priests and bishops having a better grasp of theology because they prayed, not because they studied. God reveals Himself to those who love Him. Hence the greatness of St. Dominic, St. Teresa of Avila, and St. Therese of Liseaux.
Jesuits receive mainly a secular education, with emphasis on obtaining a secular degree during their formative years as well as taking the mandatory two years of philosophy and two years of theology. Their persistent philosophizing infected society at large, especially in Europe and in Russia, which led not only the secularization of Europe, but also to the downfall of the Russian Orthodox society and their church even before Soviet times. The Renaissance was not a rebirth, but the beginning of the end of society.
While I was a Dominican Tertiary studying in college, the seminarians at the local Dominican college struggled with advanced philosophy, many leaving the seminary as atheists with inane "logical" questions like: Why is this a chair? Does a chair have existence? They told me that they felt like they were dissecting God and had destroyed Him in the process. Some of the priests struggled with agnosticism for years, so it was not surprising that they eventually fell into temptation and left the church to marry. It was a severe crisis of faith brought on by the incessant questioning of philosophy instead of unceasing prayer before God.