I'm not aware of any 'studies' comparing directly the toxicity of the protocol you used - with multiple medications - to the one here. So it's difficult to say with much conviction. However, The more antibiotics the fish is needlessly exposed to, the more the likelihood for resistance to develop - both in your tank and your home. The best 'qt' is using the safest medications for the shortest period of time, and based on the most likely organisms that are likely to be seen. This is why I favor the protocol here (which I think is more throrough). If there is evidence of a bacterial infection or an internal parasite after the protocol, then it's prudent to treat for that with antibiotics.
Fish can be carriers of something that causes no symptoms. However, so can every other animal. There are commensal organisms that can live peacefully on or inside humans, for example that can cause disease in certain circumstances (like staph or strep) or many others, but we do not treat so that we get rid of all of those bacteria.
I'm not saying that either regimen is necessarily 'bad' or 'better' - only the reason I prefer one over another.