Update. I tested both plugins side by side and they seem to work well. In the Imsanity plugin settings, I set the max width and height of the image and set the quality to 100%. Then in the ReSmush settings, I set the quality to 80%. After uploading an image with large dimensions, the resulting image met my expectations. Imsanity successfully scaled down the image dimensions while ReSmush does a fantastic job of optimizing the image for web. Imsanity does offer an image optimization feature but ReSmush does a lot better job of retaining quality at lower file sizes. I hope my findings can help someone else who wants to use both plugins simultaneously.