Have fun with the semantics and name-calling boys, but if I was building a team from scratch, the first coach I would call is Belichick. The next two would be Carroll and Harbaugh. They're that close. They're both ridiculous. It has to come down to what happens on the field then, right? I have to give it up, so far Harbaugh has the edge. It is really, really hard to argue what he's done at SF. And to give the credit to Singletary? That is just poor form. The good news is that there will be a tangible answer to this debate and it is going to be a helluva good one to watch.
I have to disagree with Kearly slightly. I don't think the coaches most important job is to build the team. I agree it is high on the list. But the good teams are all really talented. To me the most important job is to get the most out of the talent that you have. As to the OP, I would also bet that Harbaugh has almost as much control over personnel as Carroll does. The type-A coaches are involved in just about every discussion pertaining to their football team, unless they have an overbearing GM.