"How does your Troupe handle the skill humanities?"
Hmmmm, first of all, I'd say that direct knowledge of Classical Greek was almost nil in the Middle Ages (Aristotle's philosophy became known in the 1100s via Arabic translations of his Greek texts; Homer's Trojan epics existed in Latin "digest/synopsis" formats; Plato's Timaeus was essentially the best known of his works). So the Greek authors are almost universally going to be limited to Aristotle and the Latin translations of Homer, with a little Platonic aesthetics thrown in. Of course, much Greek thought still reaches Europe through the writings of the Church (Boethius, Augustine, etc.). Arabic texts--other than philosophical translations and scientific works--would also be little known.
So here's how I'd do Humanities: make it reflect the educational and pedagogical scheme of the Church schools and universities--i.e., make it reflect the Trivium (Grammar, Logic, and Rhetoric) and the Quadrivium (Astronomy, Music, Arithmetic, and Geometry). Since these seven Liberal Arts were learned sequentially (first the Trivium and then the Quadrivium, the arts within each group also being learned in sequence), increasing skill levels should indicate progression along their path. Low levels suggest someone who only got as far as the Trivium; high levels, study beyond into the Quadrivium. You could even go so far as to define Humanities as a seven-level Knowledge: lvls 1-3 correspond to the Triv., and lvls 4-7 to the Quad. So my Humanities 3 would permit me to know about Latin texts, poetic and philosophical--but I wouldn't be able to handle nasty geometric problems yet. Of course, even though that scheme would really be paradigmatic, it's not very playable. You might just want to stick to five levels (low Triv, high Quad) and have Story Guides modify rolls based on your level (Humanities 5 allowing you to pretty much make any skill test w/o a penalty, Humanities 1 or 2 causing you to suffer a minus when faced with problems involving the higher Liberal Arts).
I guess the question is this: which levels of educational achievment (Bachelor's, Master's, Doctor's, all medieval categories) correspond to which levels of Humanities skill? Or is it the case that everyone with the skill has completed the course of study and that low-level indicate that you didn't pay much attention? I personally would prefer the former--it's more interesting and more paradigmatic than the latter. In the Middle Ages, you just didn't study the classics outside of the Church or the universities. Now the Order does throw a monkey wrench of sorts into this: they might just have preserved some knowledge of Classical Greek, they're not so antsy about heretics so they'd be more likely to learn and read Arabic, they didn't have the time during apprenticeship to study at mundane/dominion schools. so you could just rule that their skill reflects a general dabbling in the Liberal Arts. But I think I'd still want to give some sort of extra credit to those, Magi or Consortes, who actually went through the process as it existed in the period.
Rob