My Mac Pro runs Win10 primarily. All 6 native SATA2 ports are occupied with drives (3 SSD, 3 HDD) and there is also an internal 3-way hardware RAID-0 that is the 'scratch' drive. Furthermore, there is a RAID-5 external made of 4 HDD's that runs as a media drive for all audio/video projects. CbB is happy in this environment with no issues.
The external backup is managed in a pair of 4-drive USB 3.0 towers. There are pictures of this in articles on my website about Homemade Hybrid Disk Drives. I turned on everything at once during testing, and despite the madness of 19 drive letters in use (there are some logical partitions) CbB never flinched.
My power profile keeps everything on, and says 'no' to any power saving spin-down options. This was initially for ensuring the SSD's didn't do anything rash, but I think other troubles have been concurrently prevented through this policy. By the way most of my 3.5 inch drives are Hitachi (HGST) 7K3000 and 7K2000's that each draw about 10-watts peak in 4k random reads, and around 7-watts at idle.