There isn't a strong pattern when narrowing to a single voice, but the ElevenLabs voices in general are much more easily mistaken for a human compared to any other provider we're currently using.
Apple doesn't publicly comment on how the chart rankings are calculated, which is why we can't draw strong conclusions, but our understanding is that this would do the job. Since the somewhat catastrophic failure of the charts a week ago its clear that Apple did update their algorithms, but its not clear how (and some of the same players identified in the blog are still ranking highly).
We can't say for sure how the charts are being gamed, but there is strong evidence that its related to a pay per play scheme to pump subscription numbers in a small time window. The implication of the graph visualization is that the same iTunes users are subscribing to all of the suspect shows, and all on one storefront (the U.S.).