Sure it can be done. Easy sets it up for you. I run 3 drives and 5 different OSs. The only problem I have ever encountered was attempting to mix an older IDE drive in with SATA drives. Never did get the IDE to boot (It would function fine as a data storage device, though).
It has been a while since I set my machine up; however, my memory says that you need to pick one OS to be the primary and install Easy there. Boot into that OS and look at "My Computer" and determine what the drive letters are. When you run Easy, then just ensure that the second/third OS is listed the same as the listing in "My Computer", and you should be "good to go".
Best to you.
Jerry in Anchorage