[Plugin: WordPress SEO by Yoast] What Would Cause Multiple Post Sitemaps? Concerned?

I recently switched over to this plugin. Thanks Yoast for your work.

One thing I noticed is that for some reason, the plugin generated 3 different sitemaps for my POSTS.

Specifically:

https://www.bmedreport.com/post-sitemap1.xml 2010-10-28 11:49
https://www.bmedreport.com/post-sitemap2.xml 2011-04-17 14:10
https://www.bmedreport.com/post-sitemap3.xml 2012-05-05 13:00

They all have different update times with one several years old.

I have this plugin on other website, and it only has 1 sitemap for POSTS.

Will this confuse the robots? 3 different sitemaps of the same website for the same posts. Any suggestions?

Thanks in advance,
Chris

https://www.ads-software.com/extend/plugins/wordpress-seo/