That was my first thought too, but the image stumped me.
With the MS approach, I found one add-in, http://onmerge.com/OnMergeImages.html but it only works with local image files, not URLs. You would have to add a feature to export the images and logos (along with privacy field) and uniquely name them so they would be compatible with how OnMerge works here http://onmerge.com/HelpImages.html
I tried AutoCrat but it is painfully slow and it (or Google) doesn’t support merging or embedding images in Docs. The API may support it but AutoCrat doesn’t.
You can display an image from a URL in Google Sheets with =IMAGE(“URL”,4,50,50) You set the size of the image by replacing 50,50 with desired dimensions.
I’ve done a lot of research and I have not found anything close to what a combination of Connections and and one of these should be able to do. If you developed a template, you could probably sell it along with your other premium items. I’d buy one!