While reading through historical documents you might encounter a couple different terms referring to the 351st. One commonly used term is "Infantry Regiment" and the other less common is "Combat Team." In short, the 351st was indeed a combat team and as such they operated differently than they did in World War I.
During the First World War divisions generally were organized around two brigades, each containing two infantry regiments. The 88th Division itself shipped out to France in 1918 with four infantry regiments, the 349th, 350th, 351st, and 352nd, who were split up into two brigades. Brigades were designed to organize troops into maximum firepower necessary to create overwhelming force in frontal assaults. They also helped maximize firepower in the front line of trench warfare. For the most part, regiments moved together as brigades more so than as individual regiments. Maneuverability was not at the top of the list for the typical infantry brigade during the first world war as that was left mostly to the horse troops. As the war progressed into the well defined lines of trench warfare and the horse troops usefulness diminished, the brigade became the base of maneuver. Yet, at the end of the war when the somewhat static lines broke loose, tanks and other vehicles showed how quickly an enemy relying on a similar brigade organization could be out maneuvered.
The Regimental Combat Team (RCT) concept gained favor after WWI when planners recognized that the next war would likely be fought on fluid battlefields like they witnessed earlier. The idea of creating smaller, self-contained versions of divisions and brigades gained momentum. This progressed to the development of the triangular division formation that eliminated the brigade and formed three regimental combat teams within an infantry division. RCTs were intended to move, attack, and resupply on their own, without delay of securing assistance from other organizations. They contained their own logistics groups (including transportation and supply), as well as artillery, engineering, and medical units. In short, though under divisional command, the combat team could operate independently by utilizing organic resources (i.e. their own resources rather than those from the division or corps), thus decreasing reaction time and increasing the speed of maneuver.
Using this triangular arrangement, the 88th Infantry Division was built around three maneuver RCTs. "Maneuver" means that they were the units designed to move and directly engage the enemy. Within each RCT there were three maneuver battalions, who in turn contained three maneuver companies comprised of three platoons. In theory, and for the most part in practice, the general intent was that one unit would attack the enemy head on, the second would provide flanking maneuver, and the third would remain in close reserve. The reserve unit was prepared to either reinforce the attack at a critical moment or stop a breakthrough counterattack by the enemy. During the advance northward of the 351st in Italy from February 1944 through October 1944 they generally followed this system.
While in the relative static positions along the Gothic Line during the winter of ’44-’45, a variation of the triangular formation was developed to provide a defense in depth. RCTs were often placed two in the line, one in reserve. Those RCTs who were in the line deployed one battalion directly on the front line, one just behind the line, and one in reserve. A system of rotation was developed such that every few days the front line battalion moved back from the line, the battalion that was just off the line moved to the rear, and the rear battalion moved into the front line. Through this rotation method battalions could integrate replacements, take on supplies, and provide some respite for the men. However, even the rear battalion in these instances were within artillery range of the enemy and also might continue to provide night patrols up to the front lines.
Yet a third system of employing the triangular concept was carried out during the Po Valley Campaign that began in April 1945. The three combat teams of the division were to “leap frog” past each other to quickly capture ground. That is, if one RCT was tied down with the enemy, the others were to bypass and continue the attack. Or, the RCTs were to bypass enemy resistance while the others "mopped up" the enemy positions. Both of these scenarios did occur as planned in the early stages of the offensive, but with the somewhat unexpected disarray of the enemy units in the valley, the RCTs on a few occasions simultaneously attacked multiple enemy objectives, advancing in multiple directions at the same time.
Because each RCT was largely self-sufficient it can create some difficulty in determining the experience of a particular soldier based on studying only the historical records of the 88th Infantry Division, or even that of the 351st. For example, on a few occasions the 351st was temporarily detached from the 88th and attached to other neighboring divisions. In these instances, they fell under the command of that other division, momentarily taking a different track than the 88th. Likewise, individual battalions within the 351st were on occasion attached to other regiments (including regiments outside of the 88th), and sometimes portions of battalions were moved independently as well. For example, reports might indicate that 1st Battalion less company C attacked an objective, or company C less one platoon was ordered in a certain direction. Sometimes a contingent would be singled out like, at 09:15 a platoon of Company A was sent to guard battalion HQ. Which platoon received such orders isn’t typically noted, and often we are left wondering if our relative was with one or the other unit.
To muddy the waters further, reports sometimes indicate a “volunteer” group was sent on a mission, or a special “combat command” was formed from elements of different units. The men who were selected for these special assignments were largely left undocumented. Patrols provide another example where men from various squads or platoons were selected to form the team, but except for the leader, it is rarely noted who was there on that dangerous mission.