Part of the appeal of the Warhammer 40000 hobby is to create your own narrative when playing the tabletop. This is one of the principal reasons the Dawn of War games have a Army painter, but apart from that, fans also probably would like to recreate famous or fabled battles that they love from the fluff or lore. Having played DOW III now, I suggest you can improve the experience further by adding unique Elites such as Space Marine Captain (in a similar function to the Diomedes unit) or Ork Warboss. It is odd to have named characters function outside of their own named armies, like Angelos supporting Raven guard in black livery. Also, why not create more unique characters in the future with their own unique abilities to encourage more interest down the line? For example, Captain Cato Sicarius or Kaptin Badrukk?