How does throwing strength relate to range? To be ...

This is not really a mathematical question because the mathematical formula for the range of a projectile is normally given in terms of starting velocity and firing angle, (the best angle being 45° up from level).
If one thinks about something like throwing a javelin, or putting the shot, the ability to achieve a high starting velocity depends upon practised technique, the mass and shape of the projectile and the weight of the thrower to some extent, and I don't think there is any known formula for that.
I suppose if you want your game to use realistic values, you could look up Olympic records for these events and try to find out what awaits a javelin thrower or shot putter can bench lift.
Or perhaps some athletics training centre could offer you statistics.
Not all that much helped by admit, but good luck.
Regards - Ian