The Eldar in the first DoW campaign were Biel-Tan, but given that Tartarus was an Altar to Khorne that was unwittingly settled by the Imperium, wouldn't it have made more sense if they were Ulthwe or Il-Kaithe? Biel-Tan only really "cleanses" Maiden and Exodite worlds, and they are led by a Farseer; Macha. I guess Eldar Craftworlds aren't Orwellian in their beliefs, but it seems a bit...odd. I suppose the Alpha Legion makes enough sense. They schemed and manipulated their way into releasing the Daemon for...whatever reason. The chosen Space Marines were a made-up chapter so they were a blank slate.
The Orks used the Blood Axes flag, but mainly used bright red and yellow. I'd also like to make note that Biel-Tan's flag varies based on whether you use their default colors or the Army Painter's. Dawn of War was the only place I saw the Biel-Tan banner that had the symbol off to the top-left and three white stripes on the opposite end, but maybe that was Macha's personal banner...?
The Eldar in Winter Assault and Dark Crusade should have been Saim-Hann instead of Ulthwe, and given they retain the Eldar's ancient traditions and more than Alaitoc, it would have made more sense if SH's main enemy were the Necrons. The Sisters of Battle in Soulstorm should have been Ebon Chalice or Bloody Rose, not the one Order that's known for pragmatism....this rant could probably go on for longer than your eyes can read.
If all of this was intentional, how would it make sense? If the factions were chosen at random, then why didn't they take the time to check the fluff and make their game's story make more sense? I couldn't decide if I was laughing or raging when being instructed how infiltration works by a Khornate Chaos Lord who uses Chaos Sorcerers and Renegade Psykers during Winter Assault's Forces of Disorder campaign.
P.S.: Seriously though, what was the inspiration to making an alternate Biel-Tan flag in the original DoW? I like the look of that one more than the basic Biel-tan flag!)