The use of both "troops" and "soldiers" for individuals can be confusing. (And then there are scout troops.)
(I don't know how many soldiers are in a squad, platoon, section, brigade,
company, or division, but I can look it up should it ever be relevant.)
Edit: Oh, and Wikipedia has this to say:
A troop is a military sub-subunit, originally a small formation of cavalry, subordinate to a squadron. In many armies a troop
is the equivalent element to the infantry section or platoon. Exceptions are the US Cavalry and the King's Troop Royal Horse
Artillery where a troop is a subunit comparable to an infantry company or artillery battery.