[Captain Kwok]

QuarianRex:

In regards to propulsion - they are several reasons why the current model was chosen. First of all, the warp core only supplies the power to the engines. It is actually the warp coils inside the nacelle that generate the propulsive forces that move the ship - aka nacelle engines for simplicity. But note that warp core tech and propulsion tech are closely linked with better engines requiring more advanced reactors. And for the other system being more simple - it is not and reduces research diversity.

I have much debate with some who wanted the Defiant as a 150kT escort! But that is not happening - it is either going to be 300kT or perhaps a 350kT new hull - which allows it to be about equal in strength to an Excelsior class ship (recall DS9 episode with the Lakota/Defiant battle). Unfortunately you cannot create mounts specifically for a single type of ship.