The colonization period in Haiti was difficult, one of the hardest ones in all the Americas, the slavery was cataloged as the cruelest ever known, and the general live conditions for middle and lower classes were not good at all.
At the bottom of the social pyramid were the slaves, however the french soldiers had really hard duties on those times, they can be cataloged like <em>¨White slaves¨</em>, obviously they haven´t to perform the slave´s work, however duties turning around the slavery, extended shifts and dreadful life conditions made their work a difficult one.
So Haitian Slaves and French soldiers were technically in a similar spot, however, the slaves had survival and another kind of advantages over the French soldiers, a key point was the resistance or partial immunity to different diseases, unfortunately, that wasn´t the French´s case.
Yellow fever was a major issue to the French forces in Haiti, debilitated the army, and was one of the key points of the posterior events (the slavery and Haiti revolutions).
So definitely the two kinds of newcomers to Haiti, haven´t the same fate, the majority of slaves adapted quickly to new territory. the opposite happened to the French soldiers.