You fail to understand.
To make it real easy for you.
Prov A: 10000 acres 10% pop sci, 150k army/troops, 90k pez, 10k wiz
Prov B: 11000 acres 0% pop sci, 150k army/troops, 90k pez, 10k wizards
Prov A will have a lower NW than prov B. Simple as that. Both provs have the same economy, except that Prov B will make slightly more gc from banks if they use banks.