The neckbeards have 50 1oz hollowpoint slugs and 50 rounds of ten pellet 0000 buckshot.
The romans are armed with body armor, shields and short swords along with some spears.
The neckbeards have a 7x7 meter 3 story bamboo castle in the middle of a Wal-Mart parking lot that the Romans are trying to take by force.
The body armor would be useless against the slugs. The concussive force of the slugs would be enought to kill through kinetic energy alone. But if the Roman's could get them to miss enough of the shots the 00 would be stopped by the vest and shild combo easily. So I'd give it to the romans.