EXO-6 Star Trek VI: The Undiscovered Country Figures

[DParga21]

True, but renaming the ship shouldn't cause it to have a complete system's failure across the board. And if it already existed as the Yamato then it should be even less likely to be in such poor condition, since you can't say it was built yesterday in a huge rush.

Yeah, that's why it's just "some". Like maybe it was in spacedock for maintenance then got renamed.
But it makes no sense that they would somehow build a brand new ship from scratch between Trek 3 and 4, especially one of a model already being phased out.
Plus, the Enterprise-A being a smaller, less powerful model of ship than the newer stuff being made is the only credible example to justify the Enterprise-G.