From Charles James's "A New and Enlarged Military Dictionary," of 1805 vintage, we find the following defintions:
CROATS. Light irregular troops. "They are ordered upon all desperate services.
ARMS. A long firelock with rifled barrel, a short bayonet, a brace of pistols. Maria Theresa employed 5,000 of these irregular troops, "the greater part of which had no pay, but lived on plunder, on the acquisition of which they are remarkably dexterous.
PANDOURS, SCLAVARIANS, who inhabit the banks of the Drave. "The pandours were originally a corps of infantry named Ruitza; and their chief occupation or duty was to clear the highroads of thieves." They first made their appearance in Germany under Baron Trenck, 1741...
Tolpatches or Talpatches. A nickname of the Hungarian foot soldier, usually used as an insult.
CRABBATES. I have not yet discovered what type of rascals these were.
Gotta love that last group, the Crabbates.