A little bit about each faction (sourced from Memory Alpha)
The Cardassian Union was formed under a treaty that established a power-sharing agreement between the Cardassian Central Command and the Obsidian Order. Friction always existed between the two organizations as the Central Command worked to expand the reaches of the Union and the Obsidian Order worked to suppress it. The civilian Detapa Council was established to serve as the chief governing body between the two branches, however, in practice, the Council was virtually powerless. (DS9: "Defiant")
The Dominion was a major galactic political power, whose influence was exerted over thousands of planets in the Gamma Quadrant. By the year 2372, the Dominion had existed for somewhere between two to ten thousand years. The Dominion was created by the Founders, a group of Changelings who resided on a rogue planet within the Omarion Nebula.
Diversity for the dominion.
We know many players wanted a solo Jem'hadar faction but that doesn't follow canon or recreate the DS9 feel so the dominion balance has been designed as best we can with overall balance in mind with the joint synergy of both Cardassian and Breen fleets added and combined to the dominion vessels.
Overall all of the vessels have their role so we challenge you as players to identify with that and show us how to utilise the factional differences as a fleet.
You can view the full dev diary explaining the above and much much more below, This is Bane signing out until next time.