Seastrat - you do have some good points and I agree with much of what you have to say.
I have been a paramedic for more than 25 years... of which, I have participated in both training and operations of the tactical variety. This has included supporting a variety of operations to include: cannibas eradication missions, high risk warrant, barricaded subject (with and without hostages, EOD, VIP protection, and special event stand-by (national security events).
I offer the above not as a boast but as evidence of participation to the point of being able to make some informed judgments and decisions.
What I see as the biggest problem in tactical EMS is the the fact that the term itself has not been defined as a specialty and has a miriad of interpretations of baseline skills and competencies.
What I do see as beneficial with immediately measurable results is the esprit de corps and level of comfort found in Special operations teams with integrated EMS of any type. I also have personally seen a great deal benefit from the "tactical medic" performing pre-planning and or creating medical threat assessments for both training and actual missions. I imaging that most of the medics would agree that we tend to treat more during training than any other place... of course with the rare serious injury or incident being mostly within real missions.
For an off the wall comparison, I would suggest that having tactical medics is a lot like forcing all persons going to and from a doctors office from a nursing home to take a paramedic staffed and expensively equipped ambulance. Just because of the "what if? question.
I prefer to call tactical EMS the necessary and expensive evil resulting from good risk management. We must try to control our risk - especially when we know that there are missions that have moderate potential for serious injury.