I have a reason for them being like that, you will see when i finnish the ships history
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Ship History
A NX Firesteel class was completed in 2387, it was a rather weak frigate, and only 1 was made, and it was decommission a few weeks, because of a warpcore defect. the ship design was different from the production run because it had photon torpedo tubes foreward, nacelle pylons with pulse phasers on them, located where a phaser array would normally be.
After the Dominion War Starfleet had a short time of peace. Then with the Reman attack on the Enterprise a long war was started with the Reman rebels. Utopia Planitia told Starfleet that it had a few nebula saucers and pods, but no Galaxy type secondary hulls. The nacelles were quickly produced and a new ship was born, the thrown together Firesteel Class,a small ship with very strong engines. It was the most advanced ship in the fleet, despite it's unfinnished look. A few of these ships were able to stop a Scimitar Class Warbird.
The ship was versitle as can be, Weapons, sensor, warp and research pods were some of the pods this ship carried, and it would rapidly replace the Springfield Class frigate.
The production run was brought into service with on the weapons pod, a heavy quantum torp tube, but no pulse phasers or nacelle pylons.the nacelle cut into the phaser arrays so the phasers got backwash power from the arrays, boosting the strength.