Empirical sources - would be a first candidate to be implemented in a skill.
And you are right about 10 credible sources are actually 2. It will look like 10 independent sources to it, real gap. Skill does prefer primary source over secondary. For example it'll prefer NASA article over blog post who cited NASA article.
I'll work on empirical sources improvement in a next releases.
I'll work on empirical sources improvement in a next releases.