I understood and implemented them. But I think I tracked down the real problem. Forget what I said about Module A, B and C for a second. Let me explain it anew:

1. Module A defines some functions that Module B calls. Module A exports these functions into Module B's namespace.

2. Module B only has one function and it is called by Module A in one of its functions. So I made Modules A use Module B.

3. When I use warnings with both Module A and B, I get 'subroutine redefined' warnings...

Do you see my error yet? I think I do. But I am unsure how to solve it. Both modules are interdependant on each other.