You can just move the Flex Bay plates to accomodate your set up. They can be re-arranged on the fly so if you have devices you can pull the face plate and move it somewhere else (or remove it altogether). So you have 4 5.25 devices, The S8 comes with:
One 1x 5.25
One 2x 5.25
Two 3x 5.25
Just remove one of the 3x 5.25 plates and the one 1x 5.25. That's 4 5.25 slots, and allows you to use the other faceplates that can be arranged as you see fit.