If you are working with a growth agency, not giving them creative control in your ad campaigns is a recipe for failure. And yet, that’s what most of the big brands do
Images and videos are the main drivers of results. The same text copy, with different images, could represent a 100% more expensive result.
You do need to provide brand guidelines, and oversight/authorize any creative that is published on your behalf. Ultimately, the agency growth analysts know which creatives work best with different audiences. That’s a critical knowledge that if you can leverage it, you can get the same results for half of the price.