which is why Data and Worf's shuttle was launched from the saucer -
Minor nitpick, but on-screen evidence seems to suggest that the shuttle was launched from the stardrive section.
It looks to me like the shuttle launches from the primary hull and flies out beside the secondary hull. Note that you can see both secondary hull engines, as opposed to just one of them.
Here's a YouTube video; the shuttle launch begins around 1:35:
Also, consider this dialog [http://www.chakoteya.net/NextGen/175.htm
WESLEY: The Borg tractor beam has moved toward the antimatter spread.
GLEASON: They might be picking up engine ionisation from the shuttle
RIKER: Data, cut your engines. Take her in unpowered.
It suggests to me that the shuttle is launched close to the antimatter spread, and ergo from the primary hull.