One vs. many -src packages for my project?

["Christian Convey" <christian.convey@gmail.com>]

I have an odd packaging situation, and was hoping someone could tell
me the best practice for this situation...

I've been asked to take an existing project and package it for use
with APT.  The project consists of many libraries and applications.

I was thinking to produce a different source package for each library
and application.

My concern is that our makefiles are hierarchial: each library and app
has its own makefile, but those makefiles pull in some "utility"
makefiles at the higher level:

myproj/make-functions1.mk
myproj/make-functions2.mk
myproj/Makefile <-- just calls 'make' on each subdirectory's makefile
myproj/libraryA/Makefile  <-- uses ../make-functions{1,2}.mk
myproj/libraryB/Makefile  <-- uses ../make-functions{1,2}.mk
myproj/appC/Makefile   <-- uses ../make-functions{1,2}.mk

So there's some overlap: both "libraryA-src.deb" and
"libraryB-src.deb" need to have "make-funtions{1,2}.mk" installed as
well.

I could create Yet Another Source Package, "myproject-common-src.deb",
that contains *only* those files that are in common.  I.e., it would
only contain "make-functions{1,2}.mk" and perhaps the top-level
Makefile.  Then package like "libraryA-src.deb" could have a package
dependency on myproject-common-src.deb.

Is this just too goofy of an approach?  Should I bit the bullet and
make the whole entire project contains just three packages?
(myproject.deb, myproject-dev.deb, and myproject-src.deb) ?

Thanks,
Christian