I was once the treasurer for a Boy Scout troop. That usage effectively describes a small but indefinite number of folk. Despite the difference in spelling, that description also applies to a "troupe" of actors, and possibly of musicians.
The plural form has long been used to describe an indefinite number of warriors. For the most part, these are soldiers (or possibly marines).
Unfortunately, that plural form has become used as a synonym for soldiers as in the ugly expression that (say) "23 troops were killed". This usage is too well entrenched to be eliminated, so that all that one can do is to deplore it.