I would like to suggest a couple of ideas(they're probably useless but I might as well try):
You could make it so that the battles(at night obv) are split into two types, hand to hand combat and ranged, so for example - night 1, Hand to hand combat(swords, knives etc.), night 2, ranged combat(bows and arrows, throwing stars etc.), night 3 hand to hand combat..... and so on
You could also(if you take up the first idea) change each player's stats according to what weapon they werent using, for example, Kat picks a sword and a bow. Her attack when using the sword is slightly lower than usual because she has a bow slung over her back, and vice versa, whereas if she picked a sword and a throwing star, her ranged attack would be slightly lower(because a throwing star isn't as powerful as a bow) but her attack when using the sword is higher because a throwing star isn't as big and bulky as a bow, so she has more room to move about. You would have to think about this for quite a while, as it would require a lot of fine tuning. You would also have to understand exactly what each person's chosen weapon was and what it could do.