Sorry, I guess I wasn’t clear.
I saw that page you referenced. There, I see two sizes, one for Featured Image (778×378) and one for Featured Content (400×300).
We are enabling Featured Content on the home page, using the Category option (three columns), as you can see here: http://37.60.237.241/~remierac/rcc/.
If I use the Featured Image (778 px x 378 px) size, will that work also for the thumbnails on the Featured Content on the home page?
Where does the Featured Content 400×300 size used?