I think maybe people are misinterpreting what Ford said. I don't think he is saying that Golden State and Minnesota have an agreement in principle that is all but done and just requires negotiation on minor points. I think what Ford is saying is that the team are in agreement on the principal players who have to be involved in any trade, but neither side is ready to pull the trigger on a deal.
I think they've established that Lee has to be involved for salary-matching and that Minnesota isn't interested unless they get Klay Thompson. Minnesota also wants Kevin Martin involved in any deal.
From Ford's point of view, this is a deal that isn't going to be killed by a disagreement over a first-round pick. Where he is probably making a mistake is in over-estimating how willing the Warriors are to give up Thompson. According to reports, the biggest voice in favor of keeping Thompson is Steve Kerr. I'm not sure you can hire Kerr and give him that contract, then immediately undercut him by trading a young player that he wants to keep. Then again, Golden State is said to have a dysfunctional front office.
On Minnesota's end, I suspect it might be Glen Taylor who is pushing for inclusion of Harrison Barnes and a first round pick, while Flip Saunders might be the guy who is willing to take less back than his owner.