I think the Heavy Cruiser Retrofit and the Fleet Heavy Cruiser Retrofit, need something that make them stand out from the mass.
They are too similar to the standart Assault Cruiser, especially the Fleet version is way to conventional IMO.
These ships have just boring BOFF layouts and have nothing that would make them attractive for anyone. They could need a bit more firepower in exchange of some survivability.
I think both ships should get a additional tactical console and two tactical BOFF stations instead of one Lt. and a Ensign Tactical. In exchange their Lt. Cmdr Engineering should be made into a Lt.
The Console Layout would look like this:
Engineering: 3 (previously: 4)
Tactical: 3 (fleet version: 4)
That way this ship would become much more interesting and something unique, instead of being just a bad Assault Cruiser clone.
Thank you for reading or ignoring, depending on who you are.
"...'With the first link, the chain is forged. The first speech censured...the first thought forbidden...the first freedom denied--chains us all irrevocably.' ... The first time any man's freedom is trodden on, we're all damaged. I fear that today--"
- Picard, quoting Judge Aaron Satie