@Aesthete: they are purely for the diorama. Maybe oneday I'll make a playable army. I have no idea which rules would be best for the subject matter. I've only been a fantasy wargamer for now.
@HappyChappy439: I'm curently experimenting a lot. For the left knight I tried to acomplish a "blued" armour. The effect looks way better in reality. The foto doesn't work that well. I painted the armour silver washed it black and then applied a thin blue wash after that I drybrushed it softly with silver and applied some highlights.
The middle one is standard silver, wash, and various highlights.
The right one is silver, black wash, silver drybrush, some selected silver highlights.
But I will try many other ways since I wan't various armour looks that were common in that period.