I absolutely love the Sovereign-Class internet "varients" but the artists should've only kitbashed one thoroughly thought-out & useful re-design. Such as:
The Marlin, keep the Galaxy X-type megaphaser(s), remove BOTH of the Galaxy-Class nacelles, & replace the overhead nacelle with the Shadow Cat's overhead mission-specific pod.
Or, the Nimitz should've been given the shadow cat's mission-specific module & the Marlin's megaphaser(s).
Maybe add a few fighters in the Nimitz's image for sense of scale. The pods the Nimitz carries beneath it should've been given their own impulse engines for the purpose of VT/OL, if they're detachable & deployed as their own Starfleet Marine headquarters / munitions locker, etc.