Hi,
Thank you for posting your question.
This document deals with how Microsoft's new patching system works as of October Microsoft Patching Changes Starting In October 2016
To answer your question, it depends if you are patching only security patches or non-security as well because the Security Only updates are not cumulative, but the Monthly Rollups (which are non-security) are cumulative. So if you are doing security, you would need to install March, April, May, June, July, August separately, but if you are doing non-security, you could use the monthly rollup for August to install all security and non-security patches through August.
Thanks!
David