The question makes plenty of sense -- if you have variance provide a range. For example, in my current run through I have unbuffed 248 and buffed I have near or over 400. In previous runs where I was less knowledgeable and far more impatient, I was generally running with 150 magic armor. So my range is from 150-248 unbuffed. Now, based on that, how easy is it for encounters in Act 1 to break through that?
What is the threshold for which armor has accomplished its goals for Act 1?
Also what encounters are we talking about? Some are almost strictly magic based whereas others are mixed.
The question makes plenty of sense, in order to proceed with the argument I have to accept your premises. I am contesting the first premise.