Federal regimental monuments can be found on most battlefields; Confederate markers are usually at the brigade level. They're sufficient to understand where an ancestor was on a battlefield during a given time interval. With a map, you can 'connect the dots' and literally follow the path of a brigade across the battlefield.

If it's of any interest, you can use markers to determine what opposing Federal units were present. For Chickamauga, I found a picture of Hilliard's Alabama Legion, 2nd Battalion involved in hand-to-hand fighting with the 11th Michigan on the crest of Snodgrass Hill. That made an impresion. We both think of that picture anytime someone tells us they're from Michigan.

Maps from Trailhead Graphics are most valuable for this kind of research. The Trailhead Graphics map for this battelfield was available at the NPS headquarters at Chickamauga when we visited. Here's the link to the Trailhead Graphics website.
http://www.trailheadgraphics.com/

To use the link click on Battlefield America Series.
Someone else may know about a complete list of burials at Marietta.