And, more broadly, the Roman army had the organization, logistics, training, weapons, and discipline to carry out Caesar’s extraordinary plan for double seige lines. The Gauls must have been astonished to see what the Romans were up to.
When the Gauls later revolted, the Treveri joined the revolt and promised the cohorts safe passage. They then ambushed them, but the Romans relinked and maintained formation, fighting until dusk. Both sides suffered heavy losses.
The surviving Romans fought their way back to the camp, but realized they now had too few men left to defend it. So they drew lots and killed themselves during the night rather than surrender.
When the Treveri went to the camp in the morning and saw this, they concluded it would be insane to keep fighting men like this and sent emissaries to Caesar asking for forgiveness and pldging loyalty to Rome.