That sounds like poor design.
You’re separating throwing into:
- a sub-optimal skill that only exists to waste the player’s time.
- a skill that can only be trained after completing a task as restrictive as forging. This skill has zero synergy with the previous skill, even if the player was using the previous skill with the exact same weapon just minutes before reading the martial arts book.
Weapons requiring different training is not enough of a reason to split skills, look at all the melee skills in the game: bashing can work both on hitting things with a rock as well as a sledgehammer, cutting can work on a knife just as well as chainsaw lajatangs, piercing can work on a shiv just as well as with a spear.
Requiring training is not something I’m fond of, it strikes again as singling out a group of weapons for no good reason, when there are plenty of other weapons that would require just as much if not more training.
A character can pick a whip or a chainsaw lajatang at skill 0 and still wield it, they can pick a minigun or a rocket launcher and have no problem reloading and shooting it (nor have any issues with firearms safety), or start using a modern hi-tech bow.
The character will suck at actually hitting things, true, and there may be better weapons to start learning, but you can still use them and train the skill all the same.