The similarities between the plots of the Madrigal of the White Magnolia and the Cold Steel games can't be just a coincidence, can they?
1. Both revolve around conflicts between the nobility and the commoners.
2. In both, two friends turned enemies, a commoner (Oscar, Crow) and a nobleman (Julius, Rean), have a duel to decide the fate of a member of a royal family (Cecilia, Cedric).
3. The blue knight is known as the Azure Knight in Sky FC and as the Azure Chevalier in CS.
4. Resurrection is involved. Aidios brings back Cecilia at the end of the Madrigal, and it seems that at least three people come back to life in the CS games: Osborne, Crow, and Rutger.
It is said at some point (by Celine, I think?) that the Divine Knights are destined to fight each other again and again. I think it's pretty tempting to assume that Julius and Oscar were Awakeners as well and that the purpose of the Knights is to help push the societal development of Zemurian countries in a particular direction, in accordance with some ancient plan.
What gives me pause is Julius' nickname, the Ruby Knight. The seven Divine Knights we know of probably correspond to the seven elements. We've already seen the Fire-aligned one, and it's known as the Vermillion Knight, not the Ruby Knight.