I don't think archer and thief are all that similar. IMO, true thief never kills and only steals. Of course, the nature of Skyrim gameplay won't let you do that. But thief would mainly focus on pickpocketing and sneaking. Hide when you are found, break in and steal etc. As for archer... Just archery. You don't have to be sneaky to be an archer. I play as a hunter which is a subclass of archer I guess.
yeah, I am thinking more in terms of role-playing. Sneaking and archery go too well together to ignore.I've been playing an archer and I would have to disagree about being sneaky. Combining the two makes for some deadly kills. If you are sneaky, they can't hear/see you and you can get the sneak bonus hits. Go up the sneak perks to get Critical Aim and you get more bonus to damage.
As for the OP question, I think it is a matter of play style. I use all the skills you mentioned and a few others. As an archer I've focused on the Archery and Sneak primarily.
yeah, I am thinking more in terms of role-playing. Sneaking and archery go too well together to ignore.