After initial organization, most regimental historians don't spend time on individual companies. Even those who were eye witnesses don't usually position them on a battlefield. Unless a company commander received orders to carry out a special mission to serve as provost guard for a military post or form a skirmish line in advance of the main line of battle, his men should be with the regiment's main body. That's what a regimental commander wanted -- more troops under his direct control available for the regiment's primary mission rather than less. If his companies had been scattered in different directions, they could be quite difficult to recall if needed quickly.

Bear in mind the small size of companies. During much of the war, a healthy-sized company might be thirty officers and men. Often it could be far less, whole regiments numbering fewer than a hundred present for duty. During the second half of the war, it becomes more difficult to find references to regiments, let alone companies. In this situation you will focus on brigades rather than regiments. For instance, National Battlefield Park markers for Confederate commands usually position brigades rather than regiments.

Anyone who wants write a company history or produce notes for a personal study still needs a regimental/brigade perspective. Once you understand regimental and brigade activities, detail from service files and pension applications of officers and men who belonged to your company will be far more meaningful. Otherwise cards and papers in a service file may look like a meaningless series of names and dates, a few place names mixed in for variety. You have to be able to read between the lines.

People may offer all kinds of exceptions to this, but in my experience the above represents your best approach to the problem. Unless your ancestor served in an artillery command, don't waste time looking for a Confederate company marker on a battlefield!