I've made it so you can tweak the settings to your liking, and make certain things more common
(The entire list of configurations is shown when you type /scoreboard players set %GAME percent_)

- To modify the config add a value (0-6) at the end of the command, 
the higher the number, the more likely it is to occur, with 6 being 100% 

(E.G. /scoreboard players set %GAME percent_skelly_bow 5)


- Mobs can spawn with any random gear up to diamond level, these items are also randomly enchanted
Skeletons and Wither Skeletons can spawn with either: Bows, Swords, Axes and a bonus shield
Zombies can spawn with either: Swords, Axes and a bonus shield

- By default there is a 0.01% chance of a horse jockey spawning,
This can be changed in the configurations

- Spiders have an extra 2 armor bars

- Zombies, Skeletons, Spiders and wither skeletons can spawn with random buffs


Finally, I've credited my name within the code itself

If there's any changes you would like to see or bugs you find, let me know and i'll get right to fixing it!

-ST