How can the impact of deploying individually rather than by unit for those who served those tours differ between those who joined the Army voluntarily and those who were conscripted for service by the Selective Service System?
In this war, the experience that the draftees had was likely worse than that of the volunteers. The policy of rotating personnel individually rather than by units had something to do with this.
Volunteers and career Army types would not have felt the impacts of this policy as deeply. They would have been motivated to be in Vietnam to some degree because they had willingly joined the army and had an ethos that reflected this choice. They would have been more inclined to do what it took to make the system work as well as it possibly good. It may be true that they would have been more disappointed than the draftees because they knew what a good Army unit should be like. However, they would likely have maintained their morale more effectively.
By contrast, draftees would not have felt disappointment. They would not have really known what to expect in the first place. They, however, would have felt more demoralized. Because they were not intrinsically motivated to be in Vietnam in the first place, unit cohesion would have been more important to them. They would have needed the cohesion that a true unit created because that cohesion would have given them a sense of purpose.
Thus, volunteers would have been more disappointed, but draftees would have been more demoralized.