I see great value in your site and I totally understand your rationale for doing this apart from steemit.

As you just explained the nature of curation groups or categories on mumble, as your site grows and multiple but similar groups exist, you might consider offering a template so that people have a way to judge one group from another. One common metric might be "originality" or uniqueness of the content. Some loose standard of criteria. It's not an easy task, and it shouldn't be too rigid. I'm thinking of some least common denominator approach, probably would need to be a different standard template for different topics.

For example music- one possible criteria might be an artist's instrument versatility (how many instruments can they play. Similar for a group called "artists" - how many types of art forms have they created works in.

For philosophy one criteria might be consistency of position or perspective, depth of thought, practicality or application to reality.

I hope you get the idea. Initially such a system of templates is probably unnecessary and perhaps not even constructive, but over time as the use of your site grows it may become very useful for curators to rank similar groups or just understand the criteria each group is guided by.