How would you balance: Mg3N2 + H2SO4 = MgSO4 + (NH4)2SO4?
You would balance it stoichiometrically. Garbage in must equal garbage out.
Is mass balanced in the equation above? Please don't trust my 'rithmetic!
Since the mass on the left hand side is precisely equivalent to the mass of the right hand side, the equation is indeed stoichiometrically balanced.
This treatment seems a bit clumsy but I can assure you that every chemist goes thru this process. You yourself do this when you make a cash or an electronic transaction. The credit that is transferred to the merchant MUST equal the debit that is made to your account. If they don't, that's when you spend hours hours on a call queue complaining about the £99-99 debit made to your account for your £9-99 purchase.