In a realistic and historical sense. For those that weren’t fresh out of basic training and thus had experienced combat before landing in France. What could the men of Captain Miller been doing?
I assume their “unit” of 8 or so men would have had to have been tied to a much larger company. After taking the beach and establishing a foothold in the area, Sgt. Horvath is seen collecting dirt from the different places he has been during his campaign. I know this sounds like I’ve answered my own question. But what I’m really asking is was the likelihood of heavy combat or worse conditions prior to this day a reality for these men? Men such as Miller and Horvath and the rest of their crew seem very comfortable giving and taking fire from the enemy whereas a lot of the other young men on the beach are visibly in complete shock.
The men in the movie are supposed to be in C "Charlie" Company of the 2nd Ranger Battalion. It was a real unit, of course, but attacked in a slightly different area of Omaha beach than portrayed in the film. The real Charlie Company of 2nd Ranger Battalion was part of a larger force assaulting Pointe de la Percée on the right flank of Omaha Beach. It is the mission slightly less famous than that performed by Force A, which assaulted Pointe du Hoc.
The 2nd and 5th Ranger battalions were created in April 1943 at Camp Forrest, Tennessee and, after extensive training, were sent directly to England to prepare for Operation Overlord. They did not fight in any other theater prior to D-Day, so the dirt-gathering is just for the movie. Famously, the 1st Ranger battalion (and the 3rd and 4th) had fought in the Mediterranean Theater prior to this under the command of the notorious Lt. Col. William Darby. They spearheaded the invasion of Sicily and were involved in several notorious adventures there, including the capture of Messina. It is possible that some of 1st/3rd/4th battalion boys might have wound up in 2nd battalion at D-Day, and therefore would have jars of dirt from previous battles, but I'm not sure on that point. There was always a bit of transferring and shuffling, so it's not totally out of the realm of possibility.
The new 2nd and 5th battalions were very well trained, however, and any modern Ranger will gladly tell you how special the WW2 Rangers were. I suspect that is why the men in the movie are portrayed as being stone cold veterans. Volunteers for the unit had to score well on physical and intelligence tests before entry. They were trained in a huge variety of combat and field skills, on a huge variety of allied and axis weapons, they learned a bit of German, and were sent to Fort Pierce, Florida, to learn amphibious assault techniques. The 2nd and 5th battalions were specifically created for their assaults on key positions during Operation Overlord.
This site has a readable but thorough and accurate account of the unit. This is also a fascinating document, and it has a little history introduction near the beginning. There is also a pretty good pop history book on the Rangers:
Bahmanyar, Shadow warriors : a history of the the US Army Rangers Oxford 2005.
edit: I have done a bit more digging since I'm in bed sick, and have found some conflicting information about the creation of the 2nd and 5th Ranger battalions on 1 April 1943. Though not necessarily an authoritative source, Haggerty (History of the Ranger Battalions in World War 2, dissertation, Fordham University 1982) says that the core of the 4th Ranger Battalion was sent back to Tennessee to form the "cadre" of the newly-formed 2nd and 5th battalions. I'm not sure exactly what that means, and I'm definitely not an expert on the personnel logistics of the United States in WW2. The 1st, 3rd, and 4th battalions had been seriously decimated by action in the Mediterranean theater, which was part of the reason why the planners wanted newly-formed and whole units for D-Day in the first place. This document suggests that the casualties were quite significant, with 1st Battalion nearly ceasing to exist. I have also found scattered references to transfers into the 2nd (and later 5th) battalion by those who had been sidelined for whatever reason in other units and wanted to get into the action. During recruitment, both for the original 1st Battalion, for the 3rd and 4th expansions (in Med. theater), and for the 2nd and 5th battalions, they preferred men with at least some basic infantry training.