My definition for Throwing in Piratez would be, 'skill to use muscle-propelled weapons that usually, but not neccesarily, have arcing shots; a primitive alternative to Firing'. That's why it's used in some melee weapons, for instance. However I'm not sure about the Mortar. It uses Firing/2 + Throwing/2 but does to not conform to the above definition. I'd preferably use Firing/2 + Intelligence/2, but there is no such stat in XCom... Any suggestions?
I would put mortar under throwing skill completely. I know it might seem strange, but look: mortar is available from the very start of the game, meaning you do not have very experienced gals. In the beggining of xcom I tend to buy a lot of soldiers, check their statistics, looking mainly for TU/firing/bravery/reactions in that order and then sack the crappy ones. Piratez adds melee somewhat in that equation but in general throwing is somewhat of a less useful skill. Obviously in the beggining your soldiers shoot like crap, so one dedicated soldier with high throwing skill is pretty usefull, but then when your other soldiers shoot better, you use less granades. In Piratez you have bows/blowpipes, so your dedicated throwing gal stays pretty useful somewhat longer, but when lasers/gauss are somewhat common I see no use for bow and dart pistols are better than blowpipes.
Dojo helps a lot with low throwing and in general I find throwing at the level of 50 to be enough for assault troops to safely use granades in combat situations, so not so much use for a dedicated thrower.
So in the mid game I see no use for high throwing skill. Correct me if I'm wrong, but there is no interesting throwing usage beside hellerium granades.
I know we could discuss logic behind every skill but we need to think of game balancing as well. You have set of just a few skills, let's make them useful. I've seen that issue multiple times with pen and paper RPG games, game balancing mechanics with character skills is tedious task
Also: If you really want to get into skill set for different weapons, quasi real life, logic and all, then light weapons like pistols might use also reaction (firing is aiming reaction is coordination of motor skills and perception); for example (firing+reaction)/2 - to reflect the fact of poor aim for non-shoulder weapons (takes way longer to aim) and the fact that in the combat situation there is no time to aim well with them. I know it is somewhat included in the accurancy of the pistols and the low TU cost, but the skill is somewhat different in real life to shoot for example dual hand mp5k and mk5 with a stock.
Same with throwing knifes - I know throwing is crucial, but with knifes you need to throw fast and flat and in combat there is no time to aim (I guess, I never used knife in a bar fight
).
Really heavy weapons might use (firing+throwing)/2 cause bipodded/tripodded heavy weapons, espacially at long distances have less in common with handheld firearms.
But then you are complicating the mechanics even more, you already need to calculate damage bonus and think which gal is the best to use specific weapon. Making the game mechanics more real-life means you need whole military chain of command to think of at every stage of the game - I know it is supposed to be mentally stimulating, but too much micromanagement is making players miserable.