The beauty of a TV show is anything is possible.
But for those of you who like Canon.
"As the dominon war was drawing to a close the Federation was designing more faster and powerful ships to replace their losses. Though the Deliverance Class was not completed in time to see combat during the war it was designed with the lessons learned.
Dr Leah Bramas and her team developed the single drive unit to allow more powerfull intergrated engines to be fitted to smaller craft like the Defiant, which as full of design problems.
Not only do the intergrated drive units or IDU's save space they are more efficent as the they share most of the same power conversion componets. Though this means a 2 second delay when switching from Impulse to Warp the trade off was deemed an improvement over the older bi-component drive systems."
Hope that helps people sleep at night with my new ship design.
