The thing that struck me when I read these is that these are surgeons discussing warfarin. My experience has been that surgeons are, for the most part, not qualified to discuss warfarin. The have almost no experience with it other than starting people on it after surgery. Surgeons cut. It is as simple as that. Most do not have the personality or temperament to be involved with people in long-term medication situations. Most of what they know about warfarin they have only read about in journals.
Last year when I was involved with the lawsuit against the NYPD the opposition had surgeons from some of the top medical schools in the country. They had given written, signed statements to the attorneys stating things like people on warfarin had died from getting punched in the stomach. They said that it was too dangerous for a police officer to have even a desk job.
I was at a meeting one time where most of the attendees were surgeons and the speaker was one too. The speaker asked how many in the audience would want a surgeon to manage their anticoagulation. Not one hand went up!
You wouldn't go to a surgeon for an allergy, so why go to one for warfarin management?
There is much better information about warfarin (from people who take it) on this website than you will get from most surgeons.