Do you plan to do a clean install?
I did a clean install and all I done was remove both HDD's that were in the laptop and installed the new SSD and carried out the clean install with only the SSD in the laptop.
Recently done a clean install of Windows 10 on a new SSD and followed the exact same procedure with no issues. Once installation was complete I added the HDD you plan to use as the secondary drive.
Hope this helps.
Asus Rog G750JW
Screen: 1920x1080 17'3 inch
CPU: i7 4700HQ
GPU: 2GB GTX 765M
RAM: 16GB 2133MHz
SDD: Samsung 850 Pro 250GB
HDD: 2TB 5400RPM