I think a merit source should uphold a higher standard regardless of which smerits they use. As opposed to non-source merit senders who can do almost whatever they please with their earned smerits.
Imho, even us non merit sources should have some standard because if I tend to merit certain type of shitposts, that can only encourage more members to do more of those as that's what those lemmings tend to do.
Ideally we should all encourage good posting habits with our merits... but let's be real, you can't expect
everyone to follow some "high quality" guidelines that would be highly subjective anyway. However you can and should expect the ~100 (or whatever the number is nowadays) merit sources to
try to avoid meriting obvious merit farmers/beggars/etc. Again, probably not possible to avoid that completely, some shitposters will be able to get some crumbs, but they're lazy AF so if they can no longer get easy merits for memes in WO they'll probably go shitpost somewhere else, where hopefully some moderation still exists and they can be reported.