I would say the first 5 or 6 could be by payout only, but then after that, using the same algorithm that sorts the trending tags on the right you could have each category with the three top posts from that tag.

There are only 2 issues I see with implementing this.

1. Repetition
   There would need to be a way to ensure that posts don't appear on the trending page twice under 2 different categories.
2. Tag abuse
   I actually chose not to order the categories exactly as the tags are in order because it would have looked so wrong. The top things in art and photography are not art or photography. And for this the whales would have to clamp down more on tag abuse as it will be more obvious when it happens. But this could also be a good thing because that will discourage tag abuse.