Out of interest, what would people think about a hand-cannon ca 1300s if it got introduced? They're realistically Medieval and are weak enough that plate, brigandine and lamellar would definitely stop it. Additionally it could act as a non-archer's weapon as the bows, crossbows and throwing weapons need proper training to be effective.
I respectfully disagree. Well, partially. Bows do indeed require lengthy specialized training (specific strength requirements, targetting skills, distance calculation etc., all done on the fly when drawing the bow). Crossbows are pre-loaded (as used) sometimes utilizing a range of tools such as cocking levers or 'winches'. This contributes to aiming times being more relaxed and the aiming itself is augumented by existence of the stock, both of which allow the weapon to be used by soldiers with just basic training and no specific muscle-building regime.
Now, the firearms. These do have just about the same advantages as the crossbow (relaxed, augumented aiming and pre-stored energy), with one major difference: the user needs to have more training in both loading (which is more complicated than crossbow, and by an order of magnitude) and setting off the charge (we are after all talking guns before all that modern flintlock or wheellock malarky) as they'd literally play with fire and could do more damage to themselves than to the enemy if they handled the weapon improperly. It's not just 'point and squeeze' of the crossbow either, due to high-maintenance matchlocks and considerable (when compared to crossbow triggering mechanism) delay between the user's decision to fire, mechanical action of firing ('squeezing the trigger) and the projectile actually leaving the weapon. Guns are also much more prone to misfire...
Nevertheless, I do think an arquebus or somesuch would be a great addition to Exanima's / Sui Generis armoury, even as an impractical novelty.
NB: I admit I know less than nothing about thrown weapons but I do imagine the training would need to be as extensive as with the bow & arrow. These do, after all, rely on individual strength as well as skill (a knife needs to hit the target with the pointy end I'd imagine).