An Audit typically takes 10-30 minutes and is primarily used as a sales tool to show value with obvious and quick improvements. While the feedback can yield returns, it has a high risk to reward ratio because of the trigger-happy nature of the feedback. I.e. they are too surface level and focused on just winning you over. Typical outputs are a long list of things that could be done, but most of them shouldn’t be done.
A Strategic Plan typically takes 3-6 hours, and focuses on reviewing about 191 high-impact aspects of Google Ads, then narrowing in on a hand-full or two of highly relevant things. I.e. a lot more things are reviewed but a few things are surfaced. The file in this link contains an example of what is reviewed. Typical outputs are a less then an Audit, however, they are strategic recommendations.
A Holistic Strategy typically takes 1-2 weeks, and covers all aspects that impact the performance of Google Ads, such as the website, and all relevant recommendations are provided. I.e. you get the quantity of an Audit and the quality of an Strategic Plan. The outputs are as in the above screenshots, highly detailed, all encompassing, and highly strategic.