I don't think you understand Archer's reasonings at all for doing what he did. You're making it more complicated than it needs to be.
But good theories none the less.
Archer btw made this entire episode. It was all about him and as I said earlier, if it weren't for the Fate arc becoming more and more apparent, I would have given this a perfect 10 as Archer just proved above all else he's the best character in Fate(game, or anime, regardless of which arc)