How about this:
The Kelvin has one Warp Nacelle.
That's fine.
We just seem to be loosing the original meaning of nacelle, and with the hull configuration of the Kelvin in particular the problem is exacerbated.
How is anyone seeing the secondary/engineering hull as anything else?
Just so there is no confusion about this - the secondary hull is on top of the saucer - we all agree about that?