well, if it wasn't for the completely wrong BOFF setup of the fleet negh'var you postet i could have agreed...you combined the hull and shield of the negh'var with everything else from the vorcha, thus creating a klingon super battle cruiser^^
and the boff layout it the most important part of a ship IMHO. So whenever the fleet assault cruiser becomes available with the specifications as seen on tribble before season 6, i'll get one...if they have the regent class boff setup, i'm gonna keep my oddy starcruiser.
I think that one possible form that the Fleet Assault Cruiser could take is a merger of the Assault Cruiser Refit and the Advanced Heavy Cruiser Retrofit. The Hull and Shields would follow what has already been established with the other Fleet Ships, and I'm not sure about the extra console slot.
The Bridge Officer layouts are nearly the same between the two. In the Assault Cruiser Refit, it is an Ensign Tactical; and in the Advanced Heavy Cruiser Retrofit, it is an Ensign Engineering. It would not be unheard of if that Ensign position to be turned into a Universal slot. That actually happened with the Patrol Escort. The Fleet Patrol Escort's Bridge Officer Layout is situated so the player can use the layout from the standard Patrol Escort or the standard Advanced Escort. So it would not be unprecedented for this to occur.
Now this next bit could be tricky. One the things that is constantly brought up when people talk about the Advanced Heavy Cruiser Retrofit, is the turn rate. And from what I understand, they would love to have a Fleet version of this ship. While it hasn't been done before, it would not be out of the realm of possibility for the Fleet Assault Cruiser to receive an increase in turn rate. If this would not happen, there will be calls for a Fleet Advanced Heavy Cruiser Retrofit, as it would still be seen as a downgrade from the Advanced Heavy Cruiser Retrofit.
Even trickier.... since both the Assault Cruiser Refit and the Advanced Heavy Cruiser Retrofit are both C-Store ships, who gets the discount on the Fleet Modules? The Assault Cruiser Refit or the Advanced Heavy Cruiser Retrofit or both? Also, would those who want their Fleet Assault Cruiser Refit, to look like the Excelsior be able to use that design? I don't know the answers to these questions, nor would I like to speculate.