Mistaken in regards to Western knights/tactics?

Though the film has been around for a few years, just had a chance to watch it.

I quite liked it, but was wondering if some of the details regarding European knights was mistaken. Primarily two facts; 1. They stated that knights didn't try to kill each other, only common soldiers, 2. That they developed 'blunt force trauma' typed of weapons in order not to kill each other (mace, etc).

I always thought that they reliance on maces and other larger weapons was due to swords being ineffective against armor, especially on horseback. They were also easier to weld in armor.

Aside from that, it was quite interesting.....