The Analyzing of "Holmesian" Logic

Sherlock Holmes.  The great detective and logician.

From what I understand from a couple of articles I have read on what those who majored in logic (or/and criminology) study is how Holmes solved his cases, the logic behind it.

I have read a few of Sherlock Holmes...books.  Safe to say, even after the case when Holmes explains how he solved the case, the information he gives is incomplete, circumstantial and merely a matter of opinion - a completely subjective analysis of the situation that can only be recreated by those who read things and people in the same kind of manner as Holmes.  For example, how does every person know that how a person bears themselves as a policeman on the beat, was a colonel in the military before retiring to become an officer?  Not everyone is very familiar with military personnel or how they carry themselves, much less those of higher rank, why someone would carry themselves differently from being in the military in general, or why one wouldn't carry themselves differently after burdening themselves with the weight of carrying out the law, whether it be just or not?  Subjective to personal knowledge, bias and overall ability to, essentially, know a person by a look.  That isn't logic.