If the quantity of matter of antimatter was switched, would it change anything?
Not really. If we were made of antimatter, we would think of matter as antimatter. Antimatter is really the same as matter, just with an opposite charge and opposite lepton/baryon numbers. The laws of physics would be virtually the same. However, if we were made of matter in a universe that was mostly antimatter, we'd have to be very careful not to get annihilated.