Interesting script idea — make the Romans sympathetic by making them vastly outnumbered and facing impossible odds.
There actually was an early Roman battle a lot like this one, except it was in Italy. All the guys got ambushed, etc. And IIRC, there really weren’t many more than seven guys who survived, and some paralyzed general telling the guys to leave without him. I just wish I could remember the name of the battle…. Was in the Punic Wars?
*looks for famous Roman battles*
Yes, that’s it. The Battle of Lake Trasimene, when Hannibal laid an ambush from up on hills. That was by a lake, though. And a lot more Romans escaped than I was remembering, which goes to show that memory can be more dramatic than the original source material!