Tiers are a method of describing how concept translates mechanically to versatility, my atheistic LG friend. Crusader, Warblade, and Swordsage are all Tier 3 classes because they have a stunning amount of options while still remaining in defined roles. Tier one classes have SO MANY OPTIONS that they simply transcend the idea of roles altogether. One cleric can be an entire adventuring party unto himself; same song and dance applies to the Wizard. As such, the question isn't, "Why should I play this remake when Cleric does it better?" but rather, "Does this remake stand on its own when placed into its role?"