The thing to remember is that the Magus class in and of itself was originally designed to fulfill the fantasy niche of the Eldritch Knight in a more updated and streamline package. Many archetypes are the result of attempts to wrestle grandfathered PrCs from past editions into a manageable form. The Eldritch Archer and to a smaller extent, Arrowsong Minstrel were attempts to rehash the spirit of Arcane Archer onto a new Pathfinder friendly chassis of mechanics.