Cherrypicking divine spell lists and shopping for lower-level variants is the whole point of the Archivist class! After all, anybody and their dogs can become Clerics just by getting ordained. So your bread-and-butter Lesser-Restoration-as-a-2nd-level-spell is pretty much available to the whole populace (in theory).
An Archivist, however, knows how the divine game is really played. He knows that many, many different approaches to miracle-working and calling on divine aid will work. He's not bound by tradition. Far from just following the catechism he got in Cleric Casting 101, he seeks out exotic mysteries, little-known rites, rarely-performed ceremonies, forgotten-about prayers.
An Archivist discovers that, even though most Clerics devoted to Pelor need a 2nd level initiation to invoke the lesser forms of restoration in body and mind, this doesn't seem to hold true for members of the Order of the Spear of the Sun, nor for the warrior-priests of the western archipelago. Those fighting brethren seem to be able to perform remarkably similar rites, right after they get inducted into the 1st circle of initiation after four years of fighting Pelor's fight. By studying these so-called 'Paladin' rituals, the Archivist can learn to perform similar rites and invoke restorative blessings at a pretty early point in his career, long before a regular Cleric would be able to call on similar miracles.
What's more, an Archivist can study rural beliefs and superstitious folklore in a way that a Cleric's oaths would forbid him. For that reason, he may come to call on elemental forces of divine origin, turning invisible, erecting walls of flame, and even shooting forth lightning bolts from his hands! He merely needs to truly understand the mish-mosh of prayers, 'magical' ceremonies, and pure superstitious belief that enables Wonderworkers, hedge wizards, witches and similar 'Adepts' to perform such feats.
A thorough search among the ancient scrolls and parchments of the Church of Devouring Flame, Kossuth the Elemental Fire Lord's most long-standing congregation, will reward the cunning Archivist with knowledge of ceremonies that will wreath him in living fire, shoot flame from his hands, even call up massive swarms of fire creatures from the Inner Planes. Most ordinary Clerics never suspect such power exists to be begged from their gods, but the priests of Kossuth know different, blessed as they are with a direct connection to his Fire Domain. An Archivist, unbound by regulations of faith, can exploit such a connection himself, even though he does not worship Kossuth.
Etc., etc.
That's the Archivist's game, his forte and his main reason for being awesome: you can and should dumpster dive through the giant masses of spells that are, in some shape or form, of divine origin! And it even makes sense from an in-game perspective!
