As for the small Warp Engines, I thought the D-10 was basically a "Heavy Battlecrusier" of the D-7 class? Basically a very beefed up version of the D-7. Besides, in GAW, the D-10 has a lot more firepower and hull capacity available in its design, yet it lacks speed and maneuvering for such a heavy hull. And since it uses many similar components of D-7 tech, maybe is not designed too be a leathal shark like a D-7 but a Heavy Hitter Battlecrusier that can take more punishment.