Straecat,
Military officers were ones who traveled with wagons full of personal furniture & supplies while families moving from one place to another might have all their worldly possessions with them on a wagon and/or horses. Based on the latter, what may have been seen in civilian camps would be what people had in their houses which would include the chairs they had at home. To say much more would be to invent a fantasy narrative...
Those points are good ones. Moving a -household- as a family unit from a settlement to find a place "out west" to settle on and establish a living, versus a frontiersman, "mountain man" or anyone on the frontier who was nomadic are different from each other. A farmstead, permanent house site and similar signs of a sedentary life versus a camp site used by one or two transients are going to be distinctly different in the material culture that would have been present.
A family that is relocating intends on setting down permanent roots. A single male, or small party of males on the move, hunting, trapping, or trading may not be able to haul more than the bare essentials.
Probate papers, wills, and other 18th century documents describing items accounted for in legal or tax papers can be very detailed. Those records, in general, indicate most families (who weren't considered "rich") living outside of towns and similar settlements, did not own much furniture. Solon Buck in his "Planting of Civilization in Western Pennsylvania" claims during the middle of the 18th century, chests and boxes in rural houses were used for seating, table top functions, etc. Chairs, and dedicated use furniture items such as purpose made tables, four poster beds, were not part of the initial settlement era furnishings.