I've often heard, and understood, that often numbers of soldiers were often heavily exaggerated, being the number of the soldiers as well as the number of camp followers I've heard that the army Frederick Barbarossa amassed for the third crusade, was mainly comprised of camp followers such as the soldiers and knights' wives, prostitutes, children, squires, etc. and this held true even in the Renaissance and beyond.
So I'm curious, was this true of the Roman Legions as well? I understand the German bands during the age of migrations did this, but they were roaming clans. So I'm just curious if the professional Roman Army practiced this as well. I suppose this heavily depends on time period though, but I'd love to hear what you guys can say on the matter!
Absolutely.
Scipio during the Second Punic War took charge of the forces in Spain and reorganised them, clearing out a lot of the camp followers and baggage handlers and making the army more self supporting.
Marius and Caesar are reported as doing similar work, along with enduring the same conditions as their men to boost morale and keep the legion disciplined (though this is a fairly standard "this is why they were so good trope" in biographies of Roman commanders.)
In the later Empire when armies were more static forts were usually surrounded by a Vicus, literally a settlement of overspill containing trade goods, relatives and everything you needed to keep an army functioning but not part of the official military structure.
Sources and further reading:
1 - Adrian Goldsworthy - The Punic Wars
2 - Jonathan P. Roth, The Logistics of the Roman Army at War (264 BC - AD 235
3 - Guy de la Bédoyère - Roman Britain: A new history.
In general the supply chain was a lot more efficient for Roman armies than later armies for a long time:
/u/HatMaster12 goes into some more details of the Roman supply system https://www.reddit.com/r/AskHistorians/comments/3q3gge/how_did_foraging_and_pillaging_for_supplies_work/