IDK I think the Warrior of Light IS seen as a tool. This actually comes to a head in the Dark Knight quest chains. Part of the reason so many people love Haurchefant is he is genuinely attached to you and sees you as a person. The Scions do not dislike you, you are family, but you are also a means to an end for them. Alphinaud calls you his "champion" and is relieved when you come out of ordeals like the Vigil unscathed because it means he won't have to find a new one. Heavensward has him actually physically traveling alongside you and him learning to see you as a friend and not a tool is actually part of his character arc.