Isn’t the difference between a mage and seer is that a mage will use there visions and knowledge for there own Benefit or go out and do what they see in there visions. While a seer will allow there knowledge to benefit others and allow the things in there visions to happen ( but both can allow or do what needs to be done ex. Terezi killing vriska is a more active thing )
I mean yes you’ve put the Active-Passive Dichotomy in a good light, but each Class specifically has a few special things that are exclusive to them, so there’s more difference between Mages and Seers, but power-wise that’d be just about it.