Judging by the script, Matthias won't start teaching Danya how to use a crossbow until at least a week from now... =(
We could, of course, arrange a kind of "final test" and have my character visit Gungnir – ask him how prepared he thinks our group is for the battle with the golem, and then proceed from there. To put a final point in this argument. But that's if we decide to go.
(He'll say, "But what do you think? Assessing the enemy is the main quality of a warrior, so you decide.")