Why fight with docs? I've been through hell with bad ENT's keeping my TSH at 5 and telling me it's all in my head. I've had docs tell me they don't like prescribing particular medications even though they're the ones I do best on. (Many docs don't do enough research on their own, many docs are rewarded by drug co's for giving certain prescriptions, many docs are just as suseptible as the rest of the public to advertising by big pharma corps... so they'll prescribe whatever's advertised the most, whoever gives them the most pretty pens and cups and brochures.) Doctors are paid by me (& my insurance co) to HELP me take care of me. They are hired by me. And if I don't get the care I want (which is to be as healthy as possible & feel as good as possible), I'll take my body (& business) somewhere else. Just like I would take my car to whichever mechanic seems to really listen, work WITH me and actually fix my car.
Many endocrinologists don't want to prescribe Armour because they have been taught (based on old info from the 70's) that Armour isn't reliable enough. There's a huge smear campaign against it. Why? For one thing, natural drugs like Armour are cheaper. It's much nicer for the drug companies to tout their synthetic drugs as FAR superior and therefore get 2 prescriptions purchased for a T4 and a T3. Armour is much cheaper than taking Synthroid & Cytomel. The docs issues are not about the T3, since now they're finally recognizing that many thyroid patients NEED T3. Their reluctance to prescribe it is due to it's image of inferiority. I had been doing GREAT on Armour and yet both new endo's I went to see (due to changing jobs & therefore insurance companies & docs) were against it for no real good reason. I asked. They couldn't give me a real reason because they had no real experience with patients on it. I convinced them to let me stay on it and then... voila... they see my numbers and agree that it's no problem for me to be on it. So I've had "I don't prescribe Armour" endos prescribing Armour and being happy with the results :-)
Not that Armour is great for everyone. The T4/T3 ratio is a little high for some people and it really is best for them to stay on a synthetic T4. But I have no functioning thyroid anymore and need full replacement and I feel 100x better on Armour than I did on Synthroid. And so, yes, I will fight docs to stay on what has turned my life around.
You asked about danger from T3. If you're getting too much, yes, that's a potential disaster. My T3 and Free T3 levels have remained in the normal range and we keep my TSH around 1, so no, I have no problems with the T3 in Armour. For some reason my body doesn't seem to be very efficient in making its own T3 from T4 so the higher level of T3 is just what I need.