They formed up the line, to charge the orcs, knowing they would die. They each knew that they would mow down dozens of orcs in their charge, only to be surrounded and fatigued before they got halfway through. They knew they were going to die, and they charged anyway. Why? Because they were brave, and someone had to kill the orcs so that their offensive would be blunted.
So they charged. They charged, and killed and charged and swung. Their charge was so successful that they actually routed the orcs, despite being outnumbered (still) 5 to 1. They stopped their charge - battered, bruised, and successful.
Then the oliphants appeared from the mist. Enormous warmachines. The Rohimirr saw them, and realised that they could not win. They'd already lived through their 'death charge', miraculously. Did they need to charge into certain death again?
They did. They formed the line, and charged (a second time) into certain death. Why?
Because it was the right thing to do.
Wow.