Oh, Travesty, at level 1, how 'skilled' are people in their weapon proficiencies anyhow? And conversely, what's the max level for these profiency skills? Presumably, with All Weapon Mastery, I won't actually be gaining any weapon profiency skills? Or do they stack on top of each other?
Yes, since All Weapon Mastery is a collective proficiency of all weapon types in this world. So technically, Ying Yue have already acquired all of the available weapon proficiency skills there is. Also, the level of her proficiency skills should be at the same level as her All Weapon Mastery skill. So if A.W.M. gained a level, so as Bow Mastery, Dagger Mastery, Spear Mastery and so on.
At level 1 they'll be able to equip the specific weapon of that proficiency. Normally, a person without a specific weapon mastery skill would suffer a penalty when equipping a weapon, say, their stamina will be drained continuously, or holding the weapon would feel uncomfortable or too heavy. Although constant training with that weapon can lead to acquiring it's proficiency skill eventually.
Also, level in proficiency skills is just a gauge on how well they use that weapon, it also affects learning sub-skills specific for that weapon mastery, the more complex the sub-skill is the higher the proficiency level required to learn it. I dont have specifics on this one tbh, like how skilled should they be at what level or on what level should they learn this skill, I'll leave that to your judgement. I assume the higher the level the stronger they are.
Let's have it capped at Level 100. This goes for all skills.
EDIT: Will be making a list of all weapon types later for reference.