Optimizing colliders for a third person character action/action RPG game

In games like Devil May Cry, Monster Hunter, and Dragon's Dogma, you are able to fight large enemies. In addition these games either allow you to do "sub-systems" damage, being able to damage and even destroy parts of an enemy, like the tail of a dragon or the engines of a space ship in space combat games, or the player is still able to damage these sub-systems but they don't really do much else than just deal damage. These games also allow the player to use different types of weapons, like swords, spears, scythes, and so on and so forth.

What kind of colliders should I use for weapons to maximize performance? Would it be ok to mix and match colliders, like using box colliders for sword weapons, but use sphere or capsule colliders for spear-like weapons? Would it be ok to use multiple colliders on large enemies? If I do use multiple colliders on large enemies,how should I go about it if I want to have sub-systems damage and have that damage affect that enemy in certain ways, like heavily damaging their legs will cause them to move slower?