Just make each ranged weapon type work with one of the colors. Something like bows do green, slings and throwing axes do yellow, spears and javelins do red and crossbows do blue. Damage scales with opening, perception and aim meter and has a penetration % according to weapon. Opening scales with mm and weapon type vs target's defensive stance. So more or less the same as melee combat except parry obviously shouldn't work at distance.
So far ranged weapons would be superior to melee because you can just spam shooting ranged weapons while a melee fighter has to spend cooldowns on restorations. To equalize the playing field a bit, it should be possible to dodge ranged attacks, ie projectiles should have movement speed. To compensate for missing a lot more, ranged weapons should generally aim faster than they do now.
With this we have three major variables for ranged weapons: damage, opening and projectile speed. This creates room for a variety of meaningfully different ranged weapons in each category. For example, a weapon can be good, OK or bad in each category, and any weapon can be good in one and bad in two categories, or OK in two and bad in one. Bows for example:
- ranger bow deals a lot of damage but needs an ally to build the green opening on target first, and it's hard to get that hit because the arrows are moving fairly slow for a bow
- hunting bow deals moderate damage and can raise opening fast enough to work for a solo archer, but it's arrows are also fairly dodgable
- shortbow has fast arrows that are almost undodgable, but they don't do much damage and take a lot of arrows to create a decent opening
- longbow has moderate speed arrows and deals moderate damage, but is slow at building openings
- recurve bow creates huge opening but has slow, low damage arrows
- composite bow has moderate speed arrows and creates opening at a decent rate, but the damage is fairly low
For weapons with ammo (ie slings, bows and crossbows), ammo should apply multipliers to the weapon's variables, and should follow the same rule (one good and two bad multipliers, or two OK and one bad).