My problem with your idea is not about adding speed or not, it's about spending precious resources at 3B rather than a higher need area. If we can get a speedster leadoff hitter that plays 2B or OF, then I'll be more on board.
My position is and almost always is we need to add pitching, pitching, pitching.
Quality over quantity.
To me, we only need to bring back Iggy, and I'll be okay with the everyday players.
I'd like to see our defense improve, but it might be too complicated to do it, this winter.