If you control multiple Pariahs enchanting different creatures, you choose which redirection effect to apply. You can't divide damage dealt by one source or combat damage dealt by multiple creatures simultaneously. For example, if a spell would deal 6 damage to you and you control multiple Pariahs, you may have that 6 damage dealt to either of the enchanted creatures instead, but you can't choose to have 3 damage dealt to each one.

If you would be dealt combat damage, the damage dealt to the enchanted creature instead is still combat damage.