How common were friendly casualties during war in the dark ages?

by MidnightRain99

I always see movies were people go to war and clash and everyone gets caught up in a fight. I get that it wasn't exactly like the movies but was it common for soldiers to kill there brothers in arms at such close range with swords or even arrows? Edit 1: Not sure if this has been ask so sorry if it has

Searocksandtrees

hi! not discouraging more responses on this time period, but meanwhile, do check out the FAQ; there's one similar post for medieval Europe

Identifying sides in battle, and avoidance/frequency of "friendly fire"