NX-100 class starship

Question, is there any reason you didn't integrate a secondary hull into design to reflect a design lineage evolution from the NV-01 towards the Daedelus/Constitution format? True, this basic design might be viewed as more warp dynamic, but as a step in the evolution of the Heavy Cruiser line, it might have been something to look at. Just and idea, otherwise, I like the beefing up of the lines, would definitely reflect an inclusion of lessons-learned from the Earth-Romulan War.