I get your point. But if you combine three medicine and you'll take the maximum dosis for the case If you take one single medicine, is the combined dosis then not too high and maybe dangerous?
I agree that if you take a too low dosis you are really screwed.
The case of secnidazole vs tinidazole:
Do you mean in general or in only your particular case? Because it is possible we have different parasites living in us. (btw you are cured as your nickname says? That'll be wonderfull for you!)