Passive Active Class Pairs
Not [100%] canon or anything. If you hate it you can completely ignore it... but I think I got some good things going on here. Active classes will appear first/be on the left.
We'll start with the confirmed pairs:
And... here are my thoughts on the matter.
Heir and Knight: Woah, what am I, crazy? Nah. I take a Knight to be someone who protects with their aspect. Dave shows examples of this throughout Sburb, such as early on when he visits himself and becomes Davesprite, and a bit later when he save John from visiting his denizen too early. Basically, Dave protects his team from doomed timelines again and again (please don't make me go out page-hunting for evidence, I assure you I'm not lying). A heir is someone who protects themselves with their aspect. In case you haven't noticed, John does this a lot. He does the windy thing when his planet is getting all burn-y, and he manages to protect himself against Bec Noir in their showdown by turning into wind. I'm sure I haven't covered everything about either class, but you can at least see my point.
Maid and Sylph: I'm pretty sure I'm not the only one who thinks this at all. Maids heal themselves with their aspect or heal their aspect (clean it up), and Sylphs heal others with their aspect.
Mage and Seer: Mages benefit themselves with knowledge of their aspect / knowledge gained through their aspect (Sollux does this a lot). Seers benefit others with knowledge of their aspect / knowledge gained through their aspect.
Witch and Page: This one might be kinda weird too. Witches manipulate their aspect / manipulate with their aspect. Witches are able to take what is already there and change it, so maybe Pages are able to manipulate what isn't really there, and make it seem like it is (or actually create it, depending on what the real definition of a Muse ends up being). Jake was able to put hope in a hopeless situation, Tavros was about to put breath into a breathless Vriska corpes (although he would've / did fail).
This would result in the Active / Passive scale looking something like this:
This all fits in to Hussie's tweet, which stated that the most active non master class is female (witch), and the two most passive non master classes are male (Page and Bard). Since Hussie did not say the two most active classes are female, the 2nd most active must either be male or non-exclusive, which Prince fits. Same goes for the other side, with Knight being a non-exclusive class. The 6 classes in the middle aren't necessarily in that exact order, but I think it's highly plausible that the classes go like that.
I know I have to expand on a lot of these, but I honestly think that this could be the answer.