SAP does not create a pulp out of the authorizations. Each instance of authorizations (even if in the same role) is it's own combination.
What you have done is the basis for the biggest flawed disasters based on belief instead of proper training about authorization concepts. Sometimes even with training people (value role fanatics) are still stronger believers than what they are useful in the long run.
Go for course ADM940 - it will help you gain a good understanding of the fundamentals. Then carry on.
Cheers,
Julius