Multiple tar.gz files could probably fix that - or requiring users to
checkout from the revision control system.
GPLv3 section 5c (note bold text):
c) You must license the entire work, as a whole, under this
License to anyone who comes into possession of a copy. This
License will therefore apply, along with any applicable section 7
additional terms, to the whole of the work, and all its parts,
regardless of how they are packaged. This License gives no
permission to license the work in any other way, but it does not
invalidate such permission if you have separately received it.
Clearly you cannot escape the terms of the GPL by splitting the work into different packages, otherwise everyone would do this.
I know I'd laugh at anyone that said that to me about my data
The GPL does not distinguish between "code" and "content", both of which are "data" aka "software". With the attitude you've presented, and given that your work is almost certainly building on the GPL licensed work owned by others, I can see legal trouble in your future.