If the saucer didn't have warp capability, they should have commanded the engineering section to zip away from them as fast and as far as possible.
It was a warp core breach that did in the stardrive section of the Enterprise.
Well, yeah, and it would have killedd the rest of the movie.
But they could have at least acknowledged the possibility.
"Sorry, sir -- it's not responding!"
or,
"Sorry, sir, but we're in its path and there's no way to reorient!"
That kind of thing.