Thats a horrible idea. If the guardian protect YOU, the mafia has a chance of randomly picking either the seer or the guardian!@guard: Please cover me today too.
That is I'm assuming that you are a townie, now if you are the seer thats good!
While if the seer himself get protected, the mafia only has a chance of randomly picking the guardian..
Thus making the mafia work finding out who is the guardian, and even when they do so, it won't kill the seer straight away, giving another full day for him
So no, I don't think leaving the seer unprotected is a good idea, if you are a townie, you are discardable.. the seer is not.
Seer should reveal himself, and the guardian should protect that person.