Hello @Rich Fleming ,
Unfortunately, there is no direct setting to remove specific infographics from the Overview page in Microsoft Sentinel. I would recommend sharing this feedback with the Product Group via the link below and maybe this will be considered in the future to be customizable.
https://feedback.azure.com/d365community/forum/79b1327d-d925-ec11-b6e6-000d3a4f06a4
If you find the answer above helpful, please Accept the answer to help anyone in the community who might have a similar question to quickly find the solution.