I hope to be able to reply you, mainly because I'm italian!!!
the corrispondent collective name to poilu or other one is MARMITTONI that mean the big pot in wich they cocked food (particularly SPAGHETTI)..
In tha famous mountain troops ALPINI there is two caratheristich nickname very common in use: BURBA that mean the young soldier enlisted few time ago and VECIO, on the counterside the experienced and long service soldier.
I hope to be usefull, excuse me for my english